Organic compounds

ABSTRACT

Optionally substituted 4,5,7,8-tetrahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine or 4,5,7,8,9-pentahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine compounds, processes for their production, their use as pharmaceuticals and pharmaceutical compositions comprising them.

This application claims priority from U.S. Provisional Application No. 61/349,952, filed May 31, 2010, the contents of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to optionally substituted 4,5,7,8-tetrahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine or 4,5,7,8,9-pentahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine compounds, preferably Compounds of Formula I as described below, processes for their production, their use as pharmaceuticals and pharmaceutical compositions comprising them. Of particular interest are novel compounds useful as inhibitors of phosphodiesterase 1 (PDE1), e.g., in the treatment of diseases involving disorders of the dopamine D1 receptor intracellular pathway, such as, among others, Parkinson's disease, depression, narcolepsy, damage to cognitive function, e.g., in schizophrenia, or disorders that may be ameliorated through enhanced progesterone-signaling pathway, e.g., female sexual dysfunction.

BACKGROUND OF THE INVENTION

Eleven families of phosphodiesterases (PDEs) have been identified but only PDEs in Family I, the Ca²⁺-calmodulin-dependent phosphodiesterases (CaM-PDEs), have been shown to mediate both the calcium and cyclic nucleotide (e.g. cAMP and cGMP) signaling pathways. The three known CaM-PDE genes, PDE1A, PDE1B, and PDE1C, are all expressed in central nervous system tissue. PDE1A is expressed throughout the brain with higher levels of expression in the CA1 to CA3 layers of the hippocampus and cerebellum and at a low level in the striatum. PDE1A is also expressed in the lung and heart. PDE1B is predominately expressed in the striatum, dentate gyrus, olfactory tract and cerebellum, and its expression correlates with brain regions having high levels of dopaminergic innervation. Although PDE1B is primarily expressed in the central nervous system, it may be detected in the heart. PDE1C is primarily expressed in olfactory epithelium, cerebellar granule cells, and striatum. PDE1C is also expressed in the heart and vascular smooth muscle.

Cyclic nucleotide phosphodiesterases decrease intracellular cAMP and cGMP signaling by hydrolyzing these cyclic nucleotides to their respective inactive 5′-monophosphates (5′ AMP and 5′ GMP). CaM-PDEs play a critical role in mediating signal transduction in brain cells, particularly within an area of the brain known as the basal ganglia or striatum. For example, NMDA-type glutamate receptor activation and/or dopamine D2 receptor activation result in increased intracellular calcium concentrations, leading to activation of effectors such as calmodulin-dependent kinase II (CaMKII) and calcineurin and to activation of CaM-PDEs, resulting in reduced cAMP and cGMP. Dopamine D1 receptor activation, on the other hand, leads to activation of nucleotide cyclases, resulting in increased cAMP and cGMP. These cyclic nucleotides in turn activate protein kinase A (PKA; cAMP-dependent protein kinase) and/or protein kinase G (PKG; cGMP-dependent protein kinase) that phosphorylate downstream signal transduction pathway elements such as DARPP-32 (dopamine and cAMP-regulated phosphoprotein) and cAMP responsive element binding protein (CREB). Phosphorylated DARPP-32 in turn inhibits the activity of protein phosphates-1 (PP-1), thereby increasing the state of phosphorylation of substrate proteins such as progesterone receptor (PR), leading to induction of physiologic responses. Studies in rodents have suggested that inducing cAMP and cGMP synthesis through activation of dopamine D1 or progesterone receptor enhances progesterone signaling associated with various physiological responses, including the lordosis response associated with receptivity to mating in some rodents. See Mani, et al., Science (2000) 287: 1053, the contents of which are incorporated herein by reference.

CaM-PDEs can therefore affect dopamine-regulated and other intracellular signaling pathways in the basal ganglia (striatum), including but not limited to nitric oxide, noradrenergic, neurotensin, CCK, VIP, serotonin, glutamate (e.g., NMDA receptor, AMPA receptor), GABA, acetylcholine, adenosine (e.g., A2A receptor), cannabinoid receptor, natriuretic peptide (e.g., ANP, BNP, CNP), DARPP-32, and endorphin intracellular signaling pathways.

Phosphodiesterase (PDE) activity, in particular, phosphodiesterase 1 (PDE1) activity, functions in brain tissue as a regulator of locomotor activity and learning and memory. PDE1 is a therapeutic target for regulation of intracellular signaling pathways, preferably in the nervous system, including but not limited to a dopamine D1 receptor, dopamine D2 receptor, nitric oxide, noradrenergic, neurotensin, CCK, VIP, serotonin, glutamate (e.g., NMDA receptor, AMPA receptor), GABA, acetylcholine, adenosine (e.g., A2A receptor), cannabinoid receptor, natriuretic peptide (e.g., ANP, BNP, CNP), endorphin intracellular signaling pathway and progesterone signaling pathway. For example, inhibition of PDE1B should act to potentiate the effect of a dopamine D1 agonist by protecting cGMP and cAMP from degradation, and should similarly inhibit dopamine D2 receptor signaling pathways, by inhibiting PDE1 activity. Chronic elevation in intracellular calcium levels is linked to cell death in numerous disorders, particularly in neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's Diseases and in disorders of the circulatory system leading to stroke and myocardial infarction. PDE1 inhibitors are therefore potentially useful in diseases characterized by reduced dopamine D1 receptor signaling activity, such as Parkinson's disease, restless leg syndrome, depression, narcolepsy and cognitive impairment. PDE1 inhibitors are also useful in diseases that may be alleviated by the enhancement of progesterone-signaling such as female sexual dysfunction.

There is thus a need for compounds that selectively inhibit PDE1 activity, especially PDE1A and/or PDE1B activity.

SUMMARY OF THE INVENTION

The invention provides optionally substituted 4,5,7,8-tetrahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine or 4,5,7,8,9-pentahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine compounds, in free or salt form, e.g., optionally substituted:

-   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine, -   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, -   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, -   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine,     -   in free or salt form, preferably (1 or 2 and/or 3 and/or 5)         substituted, more preferably with 3-oxy-substituted compounds.

In another embodiment, the invention provides a Compound of Formula I:

wherein

-   -   (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂;     -   (ii) L is a —O—;     -   (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₄ is H or C₁₋₄alkyl (e.g., methyl or isopropyl) and R₂ and         R₃ are, independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted             with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂             is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl),         -   aryl,         -   heteroaryl,         -   (optionally hetero)arylC₁₋₆alkyl, or     -    R₂ and R₃ together with the carbon to which they are attached         form a 3- to 6-membered ring; or     -    R₂ is H and R₃ and R₄ together form a di-, tri- or         tetra-methylene bridge,     -    (pref. wherein the R₃ and R₄ together have the cis         configuration, e.g., where the carbons carrying R₃ and R₄ have         the R and S configurations, respectively);     -   (v) R₅ is         -   a) -D-E-F, wherein:             -   D is a single bond, C₁₋₄alkylene (e.g., methylene,                 ethylene or prop-2-yn-1-ylene) or —C(═O)—;             -   E is a single bond, C₁₋₄alkylene (e.g., methylene,                 —C≡C—), arylene (e.g., phenylene), arylC₁₋₄alkylene                 (e.g., benzylene) or heteroarylene (e.g., pyridylene);                 and             -   F is                 -   H,                 -   aryl (e.g., phenyl),                 -   heteroaryl (e.g., pyridyl, diazolyl, triazolyl, for                     example, pyrid-2-yl, imidazol-1-yl, pyrazol-1-yl,                     1,2,4-triazol-1-yl),                 -   halo (e.g., F, Br, Cl),                 -   C₁₋₄alkyl (e.g., methyl),                 -   haloC₁₋₄alkyl (e.g., trifluoromethyl),                 -   haloC₁₋₄alkoxy,                 -   C₁₋₄alkoxy (e.g., methoxy),                 -   —C(O)—R₁₅,                 -   —N(R₁₆)(R₁₇),                 -   —S(O)₂R₂₁,                 -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or                     heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for                     example, pyrrolidin-1-yl, pyrrolidin-2-yl or                     pyrrolidin-3-yl), piperidinyl (e.g.,                     piperidin-2-yl), tetrahydro-2H-pyran-4-yl or                     morpholinyl);             -   wherein D, E and F are independently and optionally                 substituted with one or more group selected from:                 -   halo (e.g., F, Cl or Br),                 -   C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),                     haloC₁₋₄alkyl (e.g., trifluoromethyl), and                     C₁₋₄alkoxy (methoxy),             -   for example, F is heteroaryl (e.g., pyridyl (for example                 pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), thiadiazolyl (e.g.,                 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl                 or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl),                 tetrazolyl or oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl)                 optionally substituted with one or more group selected                 from halo and C₁₋₆alkyl (e.g., 4-methyl-imidazol-1-yl,                 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl,                 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl,                 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl),             -   or F is aryl, e.g., phenyl, optionally substituted with                 one or more halo (e.g., 4-fluorophenyl);             -   or F is a C₃₋₇heterocycloalkyl (e.g., pyrrolidinyl)                 optionally substituted with a C₁₋₆alkyl (e.g.,                 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl,                 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl);         -   b) a substituted heteroarylC₁₋₄alkyl, e.g., substituted with             haloC₁₋₄alkyl;         -   or         -   c) attached to one of the nitrogen atoms on the pyrazolo             portion of Formula I and is a moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and R₁₂ are independently H, halogen (e.g., Cl or F),             —C₁₋₄alkyl-N(R₂₂)(R₂₃) (e.g., aminomethyl,             isopropylaminomethyl or isobutylaminomethyl), or             —C₁₋₄alkyl-heterC₃₋₈cycloalkyl (e.g.,             pyrrolidin-1-ylmethyl), and R₁₀ is:             -   hydrogen,             -   halogen (chloro or fluoro),             -   C₁₋₄alkyl,             -   haloC₁₋₄alkyl (e.g., trifluoromethyl), haloC₁₋₄alkoxy                 (e.g., trifluoromethoxy),             -   C₁₋₄alkoxy,             -   C₃₋₇cycloalkyl,             -   hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl,                 for example piperidin-2-yl or pyrrolidin-2-yl),             -   C₁₋₄haloalkyl (e.g., trifluoromethyl),             -   aryl (e.g., phenyl),             -   heteroaryl (e.g., pyridyl (for example pyrid-2-yl,                 pyrid-3-yl, pyrid-4-yl), thiadiazolyl (e.g.,                 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl                 or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl),                 tetrazolyl or oxodiazolyl (e.g., 1,2,4-oxodiazol-3-yl),             -   arylcarbonyl (e.g., benzoyl),             -   C₁₋₄alkylsulfonyl (e.g., methylsulfonyl),             -   aminosulfonyl (e.g., —S(O)₂—N(R₁₈)(R₁₉),             -   heteroarylcarbonyl,             -   C₁₋₄alkylcarbonyl (e.g., methylcarbonyl),             -   C₁₋₄alkoxycarbonyl, (e.g., —C(O)OCH₃),             -   —C(O)OH,             -   haloC₁₋₄alkoxycarbony (e.g., trifluoromethylcarbonyl),             -   —C(O)N(R₁₈)(R₁₉), or             -   —C₁₋₄alkyl-N(R₁₈)(R₁₉) (e.g., methylaminomethyl),         -   wherein the aryl, heteroaryl, cycloalkyl and             heterocycloalkyl are independently and optionally             substituted with one or more group selected from halo (e.g.,             F or Cl), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),             C₁₋₄alkoxy, C₁₋₄haloalkyl (e.g., trifluoromethyl) and —SH;         -   For example, R₁₀ is phenyl, pyridyl, pyrazolyl, piperidinyl,             pyrrolidinyl oxadiazolyl pyrimidinyl, optionally substituted             with one or more group selected from halo (e.g., F or Cl),             C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl), C₁₋₄alkoxy,             C₁₋₄haloalkyl (e.g., trifluoromethyl) and —SH, e.g.             optionally substituted with halo or C₁₋₄alkyl, for example             R₁₀ is 1-methylpiperidin-2-yl, piperidin-2-yl,             1-ethylpiperidin-2-yl, 1-methylpyrrolidin-2-yl,             1-methylimidazol-2-yl, halopyridyl (for example             6-fluoropyrid-2-yl),         -   provided that when X, Y, or Z is nitrogen, R₈, R₉, or R₁₀,             respectively, is not present;

    -   (vi) R₆ is         -   C₁₋₄alkyl (e.g., isopropyl),         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), or         -   arylC₁₋₄alkyl (e.g., benzyl),             -   wherein the aryl or heteroaryl is optionally substituted                 with one or more group selected from halo (e.g., F, Cl),                 hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy and C₃₋₈cycloalkyl, for                 example, R₆ is 3-chlorophenyl or 4-fluorophenyl,

    -   (vii) n=0 or 1;

    -   (viii) when n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃ and R₁₄, are,         independently, H, C₁₋₄alkyl, aryl, heteroaryl, (optionally         hetero)arylC₁₋₄alkoxy or (optionally hetero)arylC₁₋₄alkyl or R₁₃         or R₁₄ can form a di-, tri- or tetramethylene bridge with R₂ or         R₄;

    -   (ix) R₁₅ is C₁₋₄alkyl (e.g., methyl), haloC₁₋₄alkyl (e.g.,         trifluoromethyl), —OH, —OC₁₋₄alkyl (e.g., —OCH₃), aryl (e.g.,         phenyl) or —N(R₁₆)(R₁₇);

    -   (x) R₁₆ and R₁₇ are independently H or C₁₋₄alkyl;

    -   (xi) R₁₈ and R₁₉ are independently         -   H,         -   C₁₋₄alky,             -   C₃ scycloalkyl,         -   heteroC₃₋₈cycloalkyl,         -   aryl (e.g., phenyl), or         -   heteroaryl,         -   wherein said aryl or heteroaryl is optionally substituted             with one or more group selected from:             -   halo (e.g., fluorophenyl, e.g., 4-fluorophenyl),             -   hydroxy (e.g., hydroxyphenyl, e.g., 4-hydroxyphenyl or                 2-hydroxyphenyl),             -   C₁₋₆alkyl,             -   haloC₁₋₆alkyl,             -   C₁₋₆alkoxy,             -   aryl,             -   heteroaryl, and             -   C₃₋₈cycloalkyl;

    -   (xii) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl;

    -   (xiii) R₂₁ is C₁₋₆alkyl (e.g., methyl) or —N(R₁₈)(R₁₉);

    -   (xiv) R₂₂ and R₂₃ are independently H or C₁₋₄alkyl (e.g.,         methyl),

    -   in free or salt form.

In another embodiment, the invention provides a Compound of Formula I as follows:

-   -   1.1 Formula I, wherein Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or         CH₂;     -   1.2 Formula I or 1.1, wherein Q is —C(═S)—;     -   1.3 Formula I or 1.1, wherein Q is —C(═O)—     -   1.4 Formula I or 1.1, wherein Q is —C(═N(R₂₀))—;     -   1.5 Formula I or 1.1, wherein Q is —CH₂—;     -   1.6 Formula I, or any of 1.1-1.5, wherein R₁ is H or C₁₋₄alkyl         (e.g., methyl or ethyl);     -   1.7 Formula 1.6, wherein R₁ is H,     -   1.8 Formula 1.6, wherein R₁ is C₁₋₄alkyl (e.g., methyl or         ethyl);     -   1.9 Formula I, or any of 1.1-1.8, wherein R₄ is H or C₁₋₄alkyl         (e.g., methyl, isopropyl) and R₂ and R₃ are, independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted             with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂             is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl),         -   aryl,         -   heteroaryl,         -   (optionally hetero)arylC₁₋₆alkoxy,         -   (optionally hetero)arylC₁₋₆alkyl, or         -   R₂ and R₃ together with the carbon to which they are             attached form a 3- to 6-membered ring;     -    or     -    R₂ is H and R₃ and R₄ together form a di-, tri- or         tetramethylene bridge,     -    (pref. wherein the R₃ and R₄ together have the cis         configuration, e.g., where the carbons carrying R₃ and R₄ have         the R and S configurations, respectively)     -   1.10 Formula 1.9, wherein R₂ or R₃ is H or C₁₋₆alkyl (e.g.,         methyl or isopropyl);     -   1.11 Formula 1.9, wherein R₂ or R₃ is H,     -   1.12 Formula 1.9, wherein R₂ or R₃ is C₁₋₆alkyl (e.g., methyl or         isopropyl);     -   1.13 Formula 1.9, wherein R₂ or R₃ is methyl;     -   1.14 Formula 1.9, wherein R₂ or R₃ is isopropyl;     -   1.15 Formula I, or any of 1.1-1.8, wherein R₂ is H and R₃ and R₄         together form a di-, tri- or tetramethylene bridge (pref.         wherein the R₃ and R₄ together have the cis configuration, e.g.,         where the carbons carrying R₃ and R₄ have the R and S         configurations, respectively);     -   1.16 Formula I or any of 1.1-1.15, wherein R₅ is -D-E-F;     -   1.17 Formula 1.16, wherein D is a single bond, C₁₋₄alkylene         (e.g., methylene, ethylene or prop-2-yn-1-ylene) or —C(═O)—;     -   1.18 Formula 1.17, wherein D is a single bond;     -   1.19 Formula 1.17, wherein D is C₁₋₄alkylene (e.g., methylene,         ethylene or prop-2-yn-1-ylene);     -   1.20 Formula 1.17, wherein D is methylene;     -   1.21 Any of formulae 1.16-1.20, wherein E is a single bond,         C₁₋₄alkylene (e.g., methylene, —C≡C—), arylene (e.g.,         phenylene), arylC₁₋₄alkylene (e.g., benzylene) or heteroarylene         (e.g., pyridylene);     -   1.22 Any of formulae 1.16-1.20, wherein E is arylene (e.g.,         phenylene);     -   1.23 Any of formulae 1.16-1.20, wherein E is phenylene;     -   1.24 Any of formulae 1.16-1.20, wherein E is heteroarylene         (e.g., pyridylene);     -   1.25 Any of formulae 1.16-1.20, wherein E is C₁₋₄alkylene (e.g.,         methylene, —C≡C—);     -   1.26 Any of formulae 1.16-1.20, wherein E is arylC₁₋₄alkylene         (e.g., benzylene);     -   1.27 Any of formulae 1.16-1.20, wherein E is a single bond;     -   1.28 Any of formulae 1.16-1.27, wherein F is         -   H,         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, diazolyl, triazolyl, for example,             pyrid-2-yl, pyrid-4-yl, pyrid-3-yl, imidazol-1-yl,             pyrazol-1-yl, 1,2,4-triazol-1-yl),         -   halo (e.g., F, Br, Cl),         -   haloC₁₋₄alkyl (e.g., trifluoromethyl),         -   haloC₁₋₄alkoxy,         -   C₁₋₄alkoxy (e.g., methoxy),         -   —C(O)—R₁₅,         -   —N(R₁₆)(R₁₇),         -   —S(O)₂R₂₁,         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or         -   heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example,             pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl),             piperidinyl (e.g., piperidin-2-yl), tetrahydro-2H-pyran-4-yl             or morpholinyl);         -   wherein F is optionally substituted with one or more group             selected from:             -   halo (e.g., F, Cl or Br),             -   C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),             -   haloC₁₋₄alkyl (e.g., trifluoromethyl),             -   C₁₋₄alkoxy, and             -   C₁₋₄alkyl (e.g., 5-methylpyrid-2-yl),             -   for example, F is heteroaryl (e.g., pyridyl, pyrazolyl                 or imidazolyl), aryl (e.g., phenyl) or                 heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example,                 pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl),                 piperidinyl (e.g., piperidin-2-yl),                 tetrahydro-2H-pyran-4-yl or morpholinyl), optionally                 substituted with one or more halo (e.g., F, Cl or Br),                 C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),                 haloC₁₋₄alkyl (e.g., trifluoromethyl), C₁₋₄alkoxy) or                 C₁₋₄alkyl (for example, F is 5-methylpyrid-2-yl,                 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl,                 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl,                 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl,                 4,6-dichloropyrid-2-yl, 4-fluorophenyl,                 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl,                 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl);     -   1.29 Formula 1.28, wherein F is H;     -   1.30 Formula 1.28, wherein F is haloC₁₋₄alkyl (e.g.,         trifluoromethyl);     -   1.31 Formula 1.28, wherein F is trifluoromethyl;     -   1.32 Formula 1.28, wherein F is halo (e.g., F, Br or Cl);     -   1.33 Formula 1.28, wherein F is Cl;     -   1.34 Formula 1.28, wherein F is heteroaryl (e.g., pyridyl (for         example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl         (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or         pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl         or oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl) optionally         substituted with one or more halo (e.g., F, Cl or Br), C₁₋₄alkyl         (e.g., methyl or prop-2-yn-1-yl), haloC₁₋₄alkyl (e.g.,         trifluoromethyl), C₁₋₄alkoxy or C₁₋₄alkyl, (e.g.,         5-trifluoromethylpyrid-2-yl, 4-methyl-imidazol-1-yl,         1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl,         3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl);     -   1.35 Formula 1.28, wherein F is heteroaryl (e.g., pyridyl,         diazolyl, triazolyl, for example, pyrid-2-yl, pyrid-4-yl,         pyrid-3-yl, imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl)         optionally substituted with one or more halo (e.g., F, Cl or         Br), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl), haloC₁₋₄alkyl         (e.g., trifluoromethyl), C₁₋₄alkoxy) or C₁₋₄alkyl;     -   1.36 Any Formulae 1.34-1.35, wherein F is pyrid-2-yl (e.g.,         pyrid-2-yl, pyrid-3-yl, pyrid-4-yl);     -   1.37 Formula 1.34, wherein F is pyridyl (e.g., pyrid-2-yl,         pyrid-3-yl, pyrid-4-yl) optionally substituted with one or more         halo (e.g., phenyl, 4-fluorophenyl or 3-chlorophenyl);     -   1.38 Formula 1.34 or 1.37, wherein F is 6-fluoropyrid-2-yl;     -   1.39 Formula 1.34 or 1.37, wherein F is 3-fluoropyrid-2-yl;     -   1.40 Formula 1.34 or 1.37, wherein F is 4-fluoropyrid-2-yl;     -   1.41 Formula 1.34, wherein F is 5-fluoropyrid-2-yl;     -   1.42 Formula 1.34, wherein F is 5-trifluoromethylpyrid-2-yl;     -   1.43 Formula 1.34, wherein F is 5-methylpyrid-2-yl;     -   1.44 Formula 1.34, wherein F is 6-thio-pyrid-2-yl;     -   1.45 Formula 1.34, wherein F is 1,2,4-triazolyl (e.g.,         1,2,4-triazolyl);     -   1.46 Any Formulae 1.34-1.35, wherein F is diazolyl (e.g.,         imidazol-1-yl or pyrazol-1-yl);     -   1.47 Formula 1.34, wherein F is imidazol-1-yl or pyrazol-1-yl;     -   1.48 Formula 1.34, wherein F is aryl (e.g., phenyl) optionally         substituted with one or more:         -   halo (e.g., F, Cl or Br),         -   C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),         -   haloC₁₋₄alkyl (e.g., trifluoromethyl),         -   C₁₋₄alkoxy or         -   C₁₋₄alkyl (e.g., 5-methylpyrid-2-yl);     -   1.49 Formula 1.34 or 1.47, wherein F is phenyl optionally         substituted with the substituents set forth in formula 1.47;     -   1.50 Formula 1.34 or 1.47, wherein F is 4-fluorophenyl or         3-chlorophenyl;     -   1.51 Formula 1.34, wherein F is C₃₋₇cycloalkyl (e.g.,         cyclopentyl, cyclohexyl) optionally substituted with one or more         halo (e.g., F, Cl or Br), C₁₋₄alkyl (e.g., methyl or         prop-2-yn-1-yl), haloC₁₋₄alkyl (e.g., trifluoromethyl),         C₁₋₄alkoxy or C₁₋₄alkyl;     -   1.52 Formula 1.51, wherein F is cyclohexyl;     -   1.53 Formula 1.51, wherein F is cyclopentyl;     -   1.54 Formula 1.28, wherein F is heteroC₃₋₇cycloalkyl (e.g.,         pyrrolidinyl (for example, pyrrolidin-1-yl, pyrrolidin-2-yl or         pyrrolidin-3-yl), piperidinyl (e.g., piperidin-2-yl),         tetrahydro-2H-pyran-4-yl or morpholinyl) optionally substituted         with one or more halo (e.g., F, Cl or Br), C₁₋₄alkyl (e.g.,         methyl or prop-2-yn-1-yl), haloC₁₋₄alkyl (e.g.,         trifluoromethyl), C₁₋₄alkoxy or C₁₋₄alkyl;     -   1.55 Formula 1.54, wherein F is pyrrolidinyl (e.g.,         pyrrolidin-3-yl, pyrrolidin-2-yl or pyrrolidin-1-yl) optionally         substituted with one or more C₁₋₄alkyl;     -   1.56 Formula 1.54, wherein F is 1-methylpyrrolidinyl or         1-ethylpyrrolidinyl;     -   1.57 Formula 1.54, wherein F is piperidinyl (e.g.,         piperidin-2-yl) optionally substituted with one or more halo         (e.g., F, Cl or Br), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),         haloC₁₋₄alkyl (e.g., trifluoromethyl), C₁₋₄alkoxy or C₁₋₄alkyl;     -   1.58 Formula 1.54 or 1.57, wherein F is piperidinyl (e.g.,         piperidin-2-yl) optionally substituted with C₁₋₄alkyl (e.g.,         methyl or prop-2-yn-1-yl);     -   1.59 Formula 1.54 or 1.57, wherein F is 1-methylpiperidin-2-yl         or 1-ethylpiperidin-2-yl;     -   1.60 Formula 1.54, wherein F is tetrahydro-2H-pyran-4-yl;     -   1.61 Formula 1.28, wherein F is aryl (e.g., phenyl) optionally         substituted with one or more halo (e.g., F, Cl or Br), C₁₋₄alkyl         (e.g., methyl or prop-2-yn-1-yl), haloC₁₋₄alkyl (e.g.,         trifluoromethyl), C₁₋₄alkoxy or C₁₋₄alkyl;     -   1.62 Formula 1.61, wherein F is phenyl;     -   1.63 Formula 1.61, wherein F is 4-fluorophenyl;     -   1.64 Formula 1.28, wherein F is —S(O)₂R₂₁ wherein R₂₁ is         C₁₋₆alkyl (e.g., methyl) or —N(R₁₈)(R₁₉);     -   1.65 Formula 1.64, wherein R₂₁ is C₁₋₆alkyl (e.g., methyl);     -   1.66 Formula 1.64, wherein R₂₁ is —N(R₁₈)(R₁₉);     -   1.67 Formula 1.28, wherein F is —C(O)—R₁₅ and R₁₅ is C₁₋₄alkyl         (e.g., methyl), haloC₁₋₄alkyl (e.g., trifluoromethyl), —OH,         —OC₁₋₄alkyl (e.g., —OCH₃), aryl (e.g., phenyl) or —N(R₁₆)(R₁₇);     -   1.68 Formula 1.28, wherein F is —C(O)—R₁₅ and R₁₅ is C₁₋₄alkyl         (e.g., methyl), haloC₁₋₄alkyl (e.g., trifluoromethyl), —OH,         —OC₁₋₄alkyl (e.g., —OCH₃), aryl (e.g., phenyl) or —N(R₁₆)(R₁₇);     -   1.69 Formula 1.68, wherein R₁₅ is C₁₋₄alkyl (e.g., methyl);     -   1.70 Formula 1.68, wherein R₁₅ is haloC₁₋₄alkyl (e.g.,         trifluoromethyl);     -   1.71 Formula 1.68, wherein R₁₅ is —OH;     -   1.72 Formula 1.68, wherein R₁₅ is —OC₁₋₄alkyl (e.g., methoxy or         ethoxy);     -   1.73 Formula 1.68, wherein R₁₅ is ethoxy;     -   1.74 Formula 1.28, wherein F is —N(R₁₆)(R₁₇);     -   1.75 Any of formulae 1.16-1.74, wherein D, E and F are         independently and optionally substituted with one or more:         -   halo (e.g., F, Cl or Br),         -   C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),         -   haloC₁₋₄alkyl (e.g., trifluoromethyl), or         -   C₁₋₄alkoxy (methoxy);     -   1.76 Formula I or any of 1.1-1.15, wherein R₅ is a substituted         heteroarylalkyl, e.g., substituted with haloalkyl;     -   1.77 Formula I or any of 1.1-1.15, wherein R₅ is attached to one         of the nitrogen atoms on the pyrazolo portion of Formula I and         is a moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and R₁₂ are independently H, halogen (e.g., Cl or F),             —C₁₋₄alkyl-N(R₂₂)(R₂₃) (e.g., aminomethyl,             isopropylaminomethyl or isobutylaminomethyl), or             —C₁₋₄alkyl-heterC₃₋₈cycloalkyl (e.g.,             pyrrolidin-1-ylmethyl), and R₁₀ is:             -   hydrogen,             -   halogen (chloro or fluoro),             -   C₁₋₄alkyl,             -   haloC₁₋₄alkyl (e.g., trifluoromethyl),             -   haloC₁₋₄alkoxy (e.g., trifluoromethoxy),             -   C₁₋₄alkoxy,             -   C₃₋₇cycloalkyl,             -   hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl,                 for example piperidin-2-yl or pyrrolidin-2-yl),             -   C₁₋₄haloalkyl (e.g., trifluoromethyl),             -   aryl (e.g., phenyl),             -   heteroaryl (e.g., pyridyl (for example pyrid-2-yl,                 pyrid-3-yl, pyrid-4-yl), thiadiazolyl (e.g.,                 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl                 or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl),                 tetrazolyl or oxodiazolyl (e.g., 1,2,4-oxodiazol-3-yl),             -   arylcarbonyl (e.g., benzoyl),             -   C₁₋₄alkylsulfonyl (e.g., methylsulfonyl),             -   aminosulfonyl (e.g., —S(O)₂—N(R₁₈)(R₁₉),             -   heteroarylcarbonyl,             -   C₁₋₄alkylcarbonyl (e.g., methylcarbonyl),             -   C₁₋₄alkoxycarbonyl, (e.g., —C(O)OCH₃),             -   —C(O)OH,             -   haloC₁₋₄alkoxycarbony (e.g., trifluoromethylcarbonyl),             -   —C(O)N(R₁₁)(R₁₉), or             -   —C₁₋₄alkyl-N(R₁₈)(R₁₉) (e.g., methylaminomethyl),         -   wherein the aryl, heteroaryl, cycloalkyl and             heterocycloalkyl are independently and optionally             substituted with one or more group selected from halo (e.g.,             F or Cl), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl),             C₁₋₄alkoxy, C₁₋₄haloalkyl (e.g., trifluoromethyl) and —SH;         -   For example, R₁₀ is phenyl, pyridyl, pyrazolyl, piperidinyl,             pyrrolidinyl oxadiazolyl pyrimidinyl, optionally substituted             with one or more group selected from halo (e.g., F or Cl),             C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl), C₁₋₄alkoxy,             C₁₋₄haloalkyl (e.g., trifluoromethyl) and —SH, e.g.             optionally substituted with halo or C₁₋₄alkyl, for example             R₁₀ is 1-methylpiperidin-2-yl, piperidin-2-yl,             1-ethylpiperidin-2-yl, 1-methylpyrrolidin-2-yl,             1-methylimidazol-2-yl, halopyridyl (for example             6-fluoropyrid-2-yl),         -   provided that when X, Y, or Z is nitrogen, R₈, R₉, or R₁₀,             respectively, is not present;

    -   1.78 Formula 1.77, wherein R₅ is a substituted heteroarylmethyl,         e.g., para-substituted with haloalkyl;

    -   1.79 Formula 1.77, wherein R₅ is a moiety of Formula A wherein         R₈, R₉, R₁₁, and R₁₂ are H and R₁₀ is phenyl;

    -   1.80 Formula 1.77, wherein R₅ is a moiety of Formula A wherein         R₈, R₉, R₁₁, and R₁₂ are H and R₁₀ is pyridyl or thiadiazolyl;

    -   1.81 Formula 1.77, wherein R₅ is a moiety of Formula A wherein         R₈, R₉, R₁₁, and R₁₂ are, independently, H or halogen, and R₁₀         is haloalkyl;

    -   1.82 Formula 1.77, wherein R₅ is a moiety of Formula A wherein         R₈, R₉, R₁₁, and R₁₂ are, independently, H, and R₁₀ is alkyl         sulfonyl;

    -   1.83 Formula I or any of 1.1-1.82, wherein R₆ is         -   C₁₋₄alkyl (e.g., isopropyl),             -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), or         -   arylC₁₋₄alkyl (e.g., benzyl),         -   wherein the aryl or heteroaryl is optionally substituted             with one or more group selected from halo (e.g., F, Cl),             hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy and C₃₋₈cycloalkyl, for             example, R₆ is 3-chlorophenyl or 4-fluorophenyl;

    -   1.84 Formula 1.83, wherein R₆ is C₁₋₄alkyl (e.g., isopropyl);

    -   1.85 Formula 1.83, wherein R₆ is C₃₋₇cycloalkyl (e.g.,         cyclopentyl or cyclohexyl);

    -   1.86 Formula 1.83, wherein R₆ is heteroaryl (e.g., pyridyl, for         example, pyrid-4-yl);

    -   1.87 Formula 1.83, wherein R₆ is arylC₁₋₄alkyl (e.g., benzyl);

    -   1.88 Formula 1.83, wherein R₆ is aryl (e.g., phenyl) optionally         substituted with one or more group selected from halo (e.g., F,         Cl), hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy and C₃₋₈cycloalkyl;

    -   1.89 Formula 1.83, wherein R₆ is fluorophenyl (e.g.,         4-fluorophenyl);

    -   1.90 Formula I or any of 1.1-1.89, wherein n=0;

    -   1.91 Formula I or any of 1.1-1.89, wherein n=1;

    -   1.92 Formula 1.91, wherein n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃         and R₁₄, are, independently, H or C₁₋₄alkyl, aryl, heteroaryl,         (optionally hetero)arylC₁₋₄alkoxy or (optionally         hetero)arylC₁₋₄alkyl;

    -   1.93 Formula I or any of 1.1-1.92, wherein R₁₆ and R₁₇ are         independently H or C₁₋₄alkyl;

    -   1.94 formula 1.93, wherein R₁₆ and R₁₇ are H,

    -   1.95 formula 1.93, wherein R₁₆ and R₁₇ are C₁₋₄alkyl;

    -   1.96 formula 1.93, wherein R₁₆ is H and R₁₇ is C₁₋₄alkyl;

    -   1.97 Formula I or any of 1.1-1.96, wherein R₁₈ and R₁₉ are         independently         -   H,         -   C₁₋₄alky,         -   C₃₋₈cycloalkyl,         -   heteroC₃₋₈cycloalkyl,         -   aryl (e.g., phenyl), or         -   heteroaryl,         -   wherein said aryl or heteroaryl is optionally substituted             with one or more group selected from:             -   halo (e.g., fluorophenyl, e.g., 4-fluorophenyl),             -   hydroxy (e.g., hydroxyphenyl, e.g., 4-hydroxyphenyl or                 2-hydroxyphenyl),             -   C₁₋₆alkyl,             -   haloC₁₋₆alkyl,             -   C₁₋₆alkoxy,             -   aryl,             -   heteroaryl, and             -   C₃₋₈cycloalkyl;

    -   1.98 Formula I or any of 1.1-1.97, wherein R₁₈ and R₁₉ are         independently H or C₁₋₄alkyl (e.g., methyl);

    -   1.99 Formula I or any of 1.1-1.98, wherein R₂₀ is H, C₁₋₄alkyl         (e.g., methyl) or C₃₋₇cycloalkyl;

    -   1.100 Formula 1.99, wherein R₂₀ is H,

    -   1.101 Formula 1.99, wherein R₂₀ is C₁₋₄alkyl (e.g., methyl);

    -   1.102 Formula 1.99, wherein R₂₀ is C₃₋₇cycloalkyl;

    -   1.103 Formula I or any of 1.1-1.102, wherein R₂₁ is C₁₋₆alkyl         (e.g., methyl) or —N(R₁₈)(R₁₉) and R₁₈ and R₁₉ are independently         H or C₁₋₄alkyl;

    -   1.104 Formula 1.103, wherein R₂₁ is C₁₋₆alkyl (e.g., methyl);

    -   1.105 Formula 1.103, wherein R₂₁ is —N(R₁₈)(R₁₉) and R₁₈ and R₁₉         are independently H or C₁₋₄alkyl;

    -   1.106 Formula I or any of 1.1-1.105, wherein R₂₂ and R₂₃ are         independently H or C₁₋₄alkyl (e.g., methyl);

    -   1.107 Formula 1.106, wherein R₂₂ and R₂₃ are H,

    -   1.108 Formula 1.106, wherein R₂₂ and R₂₃ are C₁₋₄alkyl (e.g.,         methyl);

    -   1.109 Formula 1.106, wherein R₂₂ is H and R₂₃ is C₁₋₄alkyl         (e.g., methyl);

    -   1.110 any of the preceding formulae wherein the compound is         selected from a group consisting of:

-   -   1.111 any of the preceding formulae wherein the compounds         inhibit phosphodiesterase-mediated (e.g., PDE1-mediated,         especially PDE1B-mediated) hydrolysis of cGMP, e.g., with an         IC₅₀ of less than 1 μM, preferably less than 500 nM, more         preferably less than 50 nM, still more preferably less than 10         nM, most preferably less than 1 nM in an immobilized-metal         affinity particle reagent PDE assay, for example, as described         in Example 12,

in free or salt form.

In one embodiment, the compound of formula I as described above, is a compound of Formula II:

wherein

-   -   (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂;     -   (ii) L is a —O—;     -   (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₄ is H or C₁₋₄alkyl (e.g., methyl or isopropyl) and R₂ and         R₃ are, independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted             with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂             is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl),         -   aryl,         -   heteroaryl,         -   (optionally hetero)arylC₁₋₆alkoxy, or         -   (optionally hetero)arylC₁₋₆alkyl, or     -    R₂ and R₃ together with the carbon to which they are attached         form a 3- to 6-membered ring; or     -    R₂ is H and R₃ and R₄ together form a di-, tri- or         tetramethylene bridge     -    (pref. wherein the R₃ and R₄ together have the cis         configuration, e.g., where the carbons carrying R₃ and R₄ have         the R and S configurations, respectively);     -   (v) R₅ is         -   a) -D-E-F, wherein             -   D is C₁₋₄alkylene (e.g., methylene, ethylene or                 prop-2-yn-1-ylene);             -   E is arylene (e.g., phenylene); and             -   F is aryl (e.g., phenyl), heteroaryl (e.g., pyridyl,                 diazolyl, triazolyl, for example, pyrid-2-yl,                 imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl),                 C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or                 heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example,                 pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl),                 piperidinyl (e.g., piperidin-2-yl),                 tetrahydro-2H-pyran-4-yl or morpholinyl), wherein F is                 optionally substituted with one or more halo or                 C₁₋₆alkyl (e.g., F is 4-methyl-imidazol-1-yl,                 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl,                 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl,                 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl,                 4-fluorophenyl, 1-methylpyrrolidin-3-yl,                 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or                 1-methylpiperidin-2-yl);         -   or         -   b) attached to one of the nitrogen atoms on the pyrazolo             portion of Formula II and is a moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and R₁₂ are independently H, halogen (e.g., Cl or F),             and R₁₀ is C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g.,             pyrrolidinyl or piperidinyl, for example piperidin-2-yl or             pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g.,             pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or             thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g.,             imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g.,             1,2,4-triazol-1-yl), tetrazolyl or oxadiazolyl (e.g.,             1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl,             cycloalkyl and heterocycloalkyl are independently and             optionally substituted with one or more halo (e.g., F or Cl)             or C₁₋₄alkyl, for example R₁₀ is 4-methyl-imidazol-1-yl,             1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl,             6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl,             4,6-dichloropyrid-2-yl, 4-fluorophenyl,             1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl,             1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl;

    -   (vi) R₆ is         -   C₁₋₄alkyl (e.g., isopropyl or isobutyl),         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl),         -   arylC₁₋₄alkyl (e.g., benzyl),             -   wherein the aryl or heteroaryl is optionally substituted                 with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl,                 C₁₋₆alkoxy, C₃₋₈cycloalkyl, for example, R₆ is                 isopropyl, isobutyl, cyclopentyl, cyclohexyl, phenyl,                 3-chlorophenyl or 4-fluorophenyl;

    -   (vii) n=0 or 1;

    -   (viii) when n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃ and R₁₄, are,         independently, H or C₁₋₄alkyl, aryl, heteroaryl, (optionally         hetero)arylC₁₋₄ alkoxy, (optionally hetero)arylC₁₋₄alkyl or R₁₃         or R₁₄ can form a di-, tri- or tetramethylene bridge with R₂ or         R₄;

    -   (ix) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl,

in free or salt form.

In still another embodiment, the Compound of Formula I as described above is a Compound of Formula III:

wherein

-   -   (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂;     -   (ii) L is a —O—;     -   (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₄ is H or C₁₋₄alkyl (e.g., methyl, isopropyl) and R₂ and         R₃ are, independently:         -   H,         -   C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted             with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂             is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl),         -   aryl,         -   heteroaryl,         -   (optionally hetero)arylC₁₋₆alkoxy,         -   (optionally hetero)arylC₁₋₆alkyl, or     -    R₂ and R₃ together with the carbon to which they are attached         form a 3- to 6-membered ring; or     -    R₂ is H and R₃ and R₄ together form a di-, tri- or         tetramethylene bridge     -    (pref. wherein the R₃ and R₄ together have the cis         configuration, e.g., where the carbons carrying R₃ and R₄ have         the R and S configurations, respectively);     -   (v) R₅ is         -   a) -D-E-F, wherein             -   D is C₁₋₄alkylene (e.g., methylene, ethylene or                 prop-2-yn-1-ylene);             -   E is arylene (e.g., phenylene); and             -   F is aryl (e.g., phenyl), heteroaryl (e.g., pyridyl,                 diazolyl, triazolyl, for example, pyrid-2-yl,                 imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl),                 C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or                 heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example,                 pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl),                 piperidinyl (e.g., piperidin-2-yl),                 tetrahydro-2H-pyran-4-yl or morpholinyl), wherein F is                 optionally substituted with one or more halo or                 C₁₋₆alkyl (e.g., F is 4-methyl-imidazol-1-yl,                 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl,                 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl,                 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl,                 4-fluorophenyl, 1-methylpyrrolidin-3-yl,                 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or                 1-methylpiperidin-2-yl);         -   or         -   b) attached to one of the nitrogen atoms on the pyrazolo             portion of Formula III and is a moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and

R₁₂ are independently H or halogen (e.g., Cl or F), and R₁₀ is C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl, oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more halo (e.g., F or Cl) or C₁₋₄alkyl;

-   -   (vi) R₆ is:         -   C₁₋₄alkyl (e.g., isopropyl),         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl),         -   wherein the aryl or heteroaryl is optionally substituted             with one or more halo (e.g., F or Cl), hydroxy or             Cl_(—)6alkyl, for example, R₆ is 3-chlorophenyl or             4-fluorophenyl,     -   (vii) n=0 or 1;     -   (viii) when n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃ and R₁₄, are,         independently, H or C₁₋₄alkyl, aryl, heteroaryl, (optionally         hetero)arylC₁₋₄alkoxy, (optionally hetero)arylC₁₋₄alkyl or R₁₃         or R₁₄ can form a di-, tri- or tetramethylene bridge with R₂ or         R₄;     -   (x) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl,

in free or salt form.

In still another embodiment of the invention, the Compound of Formula I is a compound of Formula IV:

wherein:

-   -   (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂;     -   (ii) L is a —O—;     -   (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₅ is         -   a) -D-E-F, wherein             -   D is C₁₋₄alkylene (e.g., methylene, ethylene or                 prop-2-yn-1-ylene);             -   E is arylene (e.g., phenylene);             -   F is aryl (e.g., phenyl), heteroaryl (e.g., pyridyl,                 diazolyl, triazolyl, for example, pyrid-2-yl,                 imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl),                 C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or                 heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example,                 pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl),                 piperidinyl (e.g., piperidin-2-yl),                 tetrahydro-2H-pyran-4-yl or morpholinyl), wherein F is                 optionally substituted with one or more halo or                 C₁₋₆alkyl (e.g., F is 4-methyl-imidazol-1-yl,                 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl,                 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl,                 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl,                 4-fluorophenyl, 1-methylpyrrolidin-3-yl,                 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or                 1-methylpiperidin-2-yl);         -   or         -   b) attached to one of the nitrogen atoms on the pyrazolo             portion of Formula IV and is a moiety of Formula A

-   -   -   wherein X, Y and Z are, independently, N or C, and R₈, R₉,             R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F),             and R₁₀ is C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g.,             pyrrolidinyl or piperidinyl, for example piperidin-2-yl or             pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g.,             pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or             thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g.,             imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g.,             1,2,4-triazol-1-yl), tetrazolyl, oxadiazolyl (e.g.,             1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl,             cycloalkyl and heterocycloalkyl are independently and             optionally substituted with one or more halo (e.g., F or             Cl), C₁₋₄alkyl;

    -   (v) R₆ is:         -   C₁₋₄alkyl (e.g., isopropyl),         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl),         -   wherein the aryl or heteroaryl is optionally substituted             with one or more halo (e.g., F, Cl), hydroxy or C₁₋₆alkyl,             for example, R₆ is 3-chlorophenyl or 4-fluorophenyl,

    -   (xi) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl, in         free or salt form.

In yet another embodiment, the Compound of Formula I is a compound of Formula V:

wherein:

-   -   (i) Q is —C(═O)—;     -   (ii) L is —O—;     -   (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo         portion of Formula V and is a moiety of Formula A

-   -   -   wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are             independently H, and R₁₀ is:             -   hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl,                 for example piperidin-2-yl or pyrrolidin-2-yl),             -   aryl (e.g., phenyl), or             -   heteroaryl (e.g., pyridyl (for example pyrid-2-yl,                 pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g.,                 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl                 or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl),                 tetrazolyl or oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl),             -   wherein the aryl, heteroaryl, cycloalkyl and                 heterocycloalkyl are independently and optionally                 substituted with one or more halo (e.g., F or Cl), C₁₋₄                 alkyl, for example R₁₀ is 4-methyl-imidazol-1-yl,                 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl,                 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl,                 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl,                 4-fluorophenyl, 1-methylpyrrolidin-3-yl,                 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or                 1-methylpiperidin-2-yl;

    -   (v) R₆ is         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl),         -   arylC₁₋₄alkyl (e.g., benzyl),             -   wherein the aryl or heteroaryl is optionally substituted                 with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl,                 C₁₋₆alkoxy, C₃₋₈cycloalkyl, for example, R₆ is                 isopropyl, isobutyl, cyclopentyl, cyclohexyl, phenyl,                 3-chlorophenyl or 4-fluorophenyl,

in free or salt form.

In another embodiment, the Compound of Formula I is a compound of Formula VI:

wherein:

-   -   (i) Q is —C(═O)—;     -   (ii) L is —O—;     -   (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo         portion of Formula VI and is a moiety of Formula A

-   -   -   wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are             independently H, and R₁₀ is selected from piperidinyl (e.g.,             piperidin-2-yl), pyrrolidinyl (e.g., pyrrolidin-2-yl),             pyridyl (for example pyrid-2-yl, pyrid-3-yl), diazolyl             (e.g., pyrazol-1-yl), 6-fluoropyrid-2-yl,             1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl,             1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl;

    -   (v) R₆ is         -   C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl),         -   aryl (e.g., phenyl),         -   heteroaryl (e.g., pyridyl, for example, pyrid-4-yl),         -   arylC₁₋₄alkyl (e.g., benzyl),             -   wherein the aryl or heteroaryl is optionally substituted                 with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl,                 C₁₋₆alkoxy, C₃₋₈cycloalkyl,             -   for example, R₆ is cyclopentyl, cyclohexyl, phenyl,                 3-chlorophenyl or 4-fluorophenyl,

in free or salt form.

In still another embodiment, the invention provides a Compound of Formula VII:

wherein:

-   -   (i) Q is —C(═O)—;     -   (ii) L is —O—;     -   (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo         portion of Formula VII and is a moiety of Formula A

-   -   -   wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are             independently H, and R₁₀ is selected from piperidinyl (e.g.,             piperidin-2-yl), pyrrolidinyl (e.g., pyrrolidin-2-yl),             pyridyl (for example pyrid-2-yl, pyrid-3-yl), diazolyl             (e.g., pyrazol-1-yl), 6-fluoropyrid-2-yl,             1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl,             1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl;

    -   (v) R₆ is selected from cyclopentyl, cyclohexyl, phenyl,         3-chlorophenyl or 4-fluorophenyl,

in free or salt form.

In still another embodiment, the invention provides a Compound of Formula VIII:

wherein:

-   -   (i) Q is —C(═O)—;     -   (ii) L is —O—;     -   (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl);     -   (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo         portion of Formula VIII and is a moiety of Formula A

-   -   -   wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are             independently H, and R₁₀ is pyrid-2-yl, 6-fluoropyrid-2-yl,             1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl,             1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl;

    -   (v) R₆ is phenyl or 4-fluorophenyl,

in free or salt form.

In still another embodiment, the invention provides a compound of any of the foregoing formulae, e.g., any of Formula I-VIII or any of formulae 1.1-1.111, wherein R₁₀ is selected from any of 3-fluoropyrid-2-yl and 4-fluoropyrid-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl.

If not otherwise specified or clear from context or unless otherwise specified, the following terms herein have the following meanings:

-   -   (a) “Alkyl” as used herein is a saturated or unsaturated         hydrocarbon moiety, preferably saturated, preferably having one         to six carbon atoms, in some instances one to four carbon atoms,         which may be linear or branched, and may be optionally mono-,         di- or tri-substituted, e.g., with halogen (e.g., chloro or         fluoro), hydroxy, or carboxy.     -   (b) “Cycloalkyl” as used herein is a saturated or unsaturated         nonaromatic hydrocarbon moiety, preferably saturated, comprising         three to nine carbon atoms, in some instances three to seven         atoms, at least some of which form a nonaromatic mono- or         bicyclic, or bridged cyclic structure, and which may be         optionally substituted, e.g., with halogen (e.g., chloro or         fluoro), hydroxy or carboxy.     -   (c) “Heterocycloalkyl” is, unless otherwise indicated, saturated         or unsaturated nonaromatic hydrocarbon moiety, preferably         saturated, comprising three to nine carbon atoms, in some         instances three to seven atoms, at least some of which form a         nonaromatic mono- or bicyclic, or bridged cyclic structure,         wherein at least one carbon atom is replaced with N, O or S,         which heterocycloalkyl may be optionally substituted, e.g., with         halogen (e.g., chloro or fluoro), hydroxy or carboxy.     -   (d) “Aryl” as used herein is a mono or bicyclic aromatic         hydrocarbon, preferably phenyl. In some instances, aryl is         optionally substituted, e.g., with alkyl (e.g., methyl), halogen         (e.g., chloro or fluoro), haloalkyl (e.g., trifluoromethyl),         hydroxy, carboxy, or an additional aryl or heteroaryl (e.g.,         biphenyl or pyridylphenyl).     -   (e) “Heteroaryl” as used herein is an aromatic moiety wherein         one or more of the atoms making up the aromatic ring is sulfur,         oxygen or nitrogen rather than carbon, e.g., pyridyl or         thiadiazolyl which may be optionally substituted, e.g., with         alkyl, halogen, haloalkyl, hydroxy or carboxy.     -   (f) Wherein E is phenylene, the numbering is as follows:

-   -   (g) It is intended that wherein the substituents end in “ene”,         for example, alkylene, phenylene or arylalkylene, said         substituents are intended to bridge or be connected to two other         substituents. Therefore, methylene is intended to be —CH₂—,         ethylene is intended to be —CH₂—CH₂— and phenylene intended to         be —C₆H₄— and arylalkylene is intended to be —C₆H₄—CH₂— or         —CH₂—C₆H₄—.     -   (h) The Compounds of the Invention are intended to be numbered         as follows:

The term “substituted,” as used herein, means that any one or more hydrogens on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency is not exceeded, and that the substitution results in a stable compound. Similarly, the substituents defined for the Compounds of the Invention are intended to result in stable compounds.

Compounds of the Invention, encompassing any of the compounds disclosed herein, e.g., optionally substituted 4,5,7,8-tetrahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine or 4,5,7,8,9-pentahydro-(1H or 2H)-(optionally 4-oxo, 4-thioxo or 4-imino)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine compounds, e.g., (1 or 2 and/or 3 and/or 5)-substituted: 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine, 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine, 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine, 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine compounds, e.g., Compounds of Formula I, e.g., any of formulae 1.1-1.111, or Compounds of any of Formulae II-VIII as described herein, may exist in free or salt form, e.g., as acid addition salts. In this specification unless otherwise indicated, language such as “Compounds of the Invention” is to be understood as embracing the compounds in any form, for example free or acid addition salt form, or where the compounds contain acidic substituents, in base addition salt form. The Compounds of the Invention are intended for use as pharmaceuticals, therefore pharmaceutically acceptable salts are preferred. Salts which are unsuitable for pharmaceutical uses may be useful, for example, for the isolation or purification of free Compounds of the Invention or their pharmaceutically acceptable salts, are therefore also included. In particular embodiment, the salt of the compounds of the invention is a formic acid addition salt.

Compounds of the Invention may in some cases also exist in prodrug form. A prodrug form is compound which converts in the body to a Compound of the Invention. For example when the Compounds of the Invention contain hydroxy or carboxy substituents, these substituents may form physiologically hydrolysable and acceptable esters. As used herein, “physiologically hydrolysable and acceptable ester” means esters of Compounds of the Invention which are hydrolysable under physiological conditions to yield acids (in the case of Compounds of the Invention which have hydroxy substituents) or alcohols (in the case of Compounds of the Invention which have carboxy substituents) which are themselves physiologically tolerable at doses to be administered. Therefore, wherein the Compound of the Invention contains a hydroxy group, for example, Compound-OH, the acyl ester prodrug of such compound, for example, Compound-O—C(O)—C₁₋₄alkyl, can hydrolyze in the body to form physiologically hydrolysable alcohol (Compound-OH) on the one hand and acid on the other (e.g., HOC(O)—C₁₋₄alkyl). Alternatively, wherein the Compound of the Invention contains a carboxylic acid, for example, Compound-C(O)OH, the acid ester prodrug of such compound, for example, Compound-C(O)O—C₁₋₄alkyl can hydrolyze to form Compound-C(O)OH and HO—C₁₋₄alkyl. As will be appreciated the term thus embraces conventional pharmaceutical prodrug forms.

The invention also provides methods of making the Compounds of the Invention and methods of using the Compounds of the Invention for treatment of diseases and disorders as set forth below (especially treatment of diseases characterized by reduced dopamine D1 receptor signaling activity, such as Parkinson's disease, Tourette's Syndrome, Autism, fragile X syndrome, ADHD, restless leg syndrome, depression, cognitive impairment of schizophrenia, narcolepsy and diseases that may be alleviated by the enhancement of progesterone-signaling such as female sexual dysfunction), or a disease or disorder such as psychosis or glaucoma). This list is not intended to be exhaustive and may include other diseases and disorders as set forth below.

In another embodiment, the invention further provides a pharmaceutical composition comprising a Compound of the Invention, in free or pharmaceutically acceptable salt form, in admixture with a pharmaceutically acceptable carrier.

DETAILED DESCRIPTION OF THE INVENTION

Methods of Making Compounds of the Invention

The compounds of the Invention and their pharmaceutically acceptable salts may be made using the methods as described and exemplified herein and by methods similar thereto and by methods known in the chemical art. Such methods include, but not limited to, those described below. If not commercially available, starting materials for these processes may be made by procedures, which are selected from the chemical art using techniques which are similar or analogous to the synthesis of known compounds. Various starting materials and/or Compounds of the Invention may be prepared using methods described in WO 2006/133261; WO 2009/075784; PCT/US2009/06438 (or WO 2010/065148); PCT/US2009/006442 (or WO 2010/065151) and PCT/US2009/006439 (or WO 2010/065149). All references cited herein are hereby incorporated by reference in their entirety.

The Compounds of the Invention include their enantiomers, diastereoisomers and racemates, as well as their polymorphs, hydrates, solvates and complexes. Some individual compounds within the scope of this invention may contain double bonds. Representations of double bonds in this invention are meant to include both the E and the Z isomer of the double bond. In addition, some compounds within the scope of this invention may contain one or more asymmetric centers. This invention includes the use of any of the optically pure stereoisomers as well as any combination of stereoisomers.

As will be appreciated by those skilled in the art, the Compounds of the Invention may exhibit keto-enol tautomerization. Therefore, the invention as defined in the present invention is to be understood as embracing both the structures as set forth herewith and their tautomeric forms.

It is also intended that the Compounds of the Invention encompass their stable and unstable isotopes. Stable isotopes are nonradioactive isotopes which contain one additional neutron compared to the abundant nuclides of the same species (i.e., element). It is expected that the activity of compounds comprising such isotopes would be retained, and such compound would also have utility for measuring pharmacokinetics of the non-isotopic analogs. For example, the hydrogen atom at a certain position on the Compounds of the Invention may be replaced with deuterium (a stable isotope which is non-radioactive). Examples of known stable isotopes include, but not limited to, deuterium, ¹³C, ¹⁵N, ¹⁸O. Alternatively, unstable isotopes, which are radioactive isotopes which contain additional neutrons compared to the abundant nuclides of the same species (i.e., element), e.g., ²³I, ¹³¹I, ¹²⁵I, ¹¹C, ¹⁸F, may replace the corresponding abundant species, e.g., I, C and F respectively. Another example of useful isotope of the compound of the invention is the ¹¹C isotope. These radio isotopes are useful for radio-imaging and/or pharmacokinetic studies of the compounds of the invention. Methods of making isotopes of PDE1 inhibitors disclosed in WO 2011/043816, the contents of which are incorporated by reference in their entirety, may be used for making the isotopes of the compounds of the current invention.

Melting points are uncorrected and (dec) indicates decomposition. Temperature are given in degrees Celsius (° C.); unless otherwise stated, operations are carried out at room or ambient temperature, that is, at a temperature in the range of 18-25° C. Chromatography means flash chromatography on silica gel; thin layer chromatography (TLC) is carried out on silica gel plates. NMR data is in the delta values of major diagnostic protons, given in parts per million (ppm) relative to tetramethylsilane (TMS) as an internal standard. Conventional abbreviations for signal shape are used. Coupling constants (J) are given in Hz. For mass spectra (MS), the lowest mass major ion is reported for molecules where isotope splitting results in multiple mass spectral peaks Solvent mixture compositions are given as volume percentages or volume ratios. In cases where the NMR spectra are complex, only diagnostic signals are reported.

Terms and abbreviations:

-   -   BOP=(Benzotriazole-1-yl-oxy)tris(dimethylamino)-phosphonium         hexafluorophosphate,     -   BuLi=n-butyllithium,     -   Bu^(t)OH=tert-butyl alcohol,     -   CAN=ammonium cerium (IV) nitrate,     -   DBU=1,8-Diazabicyclo[5.4.0]undec-7-ene,     -   DIPEA=diisopropylethylamine,     -   DMF=N,N-dimethylforamide,     -   DMSO=dimethyl sulfoxide,     -   Et₂O=diethyl ether,     -   EtOAc=ethyl acetate,     -   equiv.=equivalent(s),     -   h=hour(s),     -   HPLC=high performance liquid chromatography,     -   K₂CO₃=potassium carbonate     -   LiHMDS=lithium bis(trimethylsilyl)amide     -   LDA=lithium diisopropylamide     -   MeOH=methanol,     -   NBS=N-bromosuccinimide,     -   NCS=N-chlorosuccinimide,     -   NaHCO₃=sodium bicarbonate,     -   NH₄OH=ammonium hydroxide,     -   Pd₂ (dba)₃=tris[dibenzylideneacetone]dipalladium(0)     -   PMB=p-methoxybenzyl,     -   POCl₃=phosphorous oxychloride,     -   SOCl₂=thionyl chloride,     -   TFA=trifluoroacetic acid,     -   TFMSA=trifluoromethanesulfonic acid     -   THF=tetrahedrofuran.

The synthetic methods in this invention are illustrated below. The significances for the R groups are as set forth above for formula I-VIII or any of formulae 1.1-1.111 unless otherwise indicated.

In an aspect of the invention, intermediate compounds of formula IIb can be synthesized by reacting a compound of formula IIa with a dicarboxylic acid, acetic anhydride and acetic acid mixing with heat, e.g., to about 90° C. for about 3 hours and then cooled:

-   -   wherein R¹ is methyl.

Intermediate IIc can be prepared by for example reacting intermediate IIb with for example a chlorinating compound such as POCl₃, sometimes with small amounts of water and heat, e.g., heating to about 80° C. for about 4 hours and then cooled:

Intermediate IId may be formed by reacting intermediate IIc with for example a P¹-L in a solvent such as DMF and a base such as K₂CO₃, sodium bicarbonate, cesium carbonate, sodium hydroxide, triethylamine, diisopropylethylamine or the like at room temperature or with heating:

-   -   wherein P¹ is a protective group [e.g., p-methoxybenzyl group         (PMB) or BOC]; L is a leaving group such as a halogen, mesylate,         or tosylate. Preferably, P¹ is PMB and the base is potassium         carbonate.

Intermediate IIe may be prepared by reacting intermediate IId with hydrazine or hydrazine hydrate in a solvent such as methanol and with heating, e.g. refluxed for about 4 hours and then cooled:

Intermediate IVa may be formed by for example reacting intermediate IIe with POCl₃ and DMF:

-   -   wherein R¹ is as defined previously, such as a methyl group.

Intermediate IVb may be formed by reacting intermediate IVa with for example a R₅—X in a solvent such as DMF and a base such as K₂CO₃, sodium bicarbonate, cesium carbonate, triethylamine or the like at room temperature or with heating (Reaction 1):

Intermediate IVc may be synthesized from intermediate IVb by removing the protective group P¹ with an appropriate method. For example, if P¹ is a PMB group, then it can be removed with CAN or TFA/TFMSA at room temperature (Reaction 2):

-   -   Wherein P¹ is BOC, the compound may be deprotected by using acid         such as hydrochloric acid or TFA.

Intermediate IVd can be prepared by reacting intermediate IVc with for example a chlorinating compound such as POCl₃ and optionally with heating, e.g., reflux for about 2 days, or heated at 150-200° C. for about 5-10 min in a sealed vial with a microwave instrument and then cooled (Reaction 3):

Intermediate IVe can be formed by reacting a intermediate IVd with an amino alcohol under basic condition in a solvent such as DMF and heated overnight then cooled (Reaction 4A):

-   -   Alternatively, intermediate IVe can be synthesized directly from         intermediate IVc by reacting with an amino alcohol and a         coupling reagent such as BOP in the presence of a base such as         DBU (Reaction 4B):

-   -   wherein all the substituents are as defined previously.

Intermediate IVf may be formed by reacting a compound of IVe with for example a dehydrating/halogenating agent such as SOCl₂ in a solvent such as CH₂Cl₂ at room temperature overnight or heated at 35° C. for several hours, and then cooled (Reaction 5):

Intermediate IVg wherein X is halogen (e.g., chloro) may be formed by reacting intermediate IVf with for example a halogenating agent such as hexachloroethane, NCS, NBS, I₂ and a base such as LiHMDS in a solvent such as THF at low temperature for several hours (Reaction 6).

The Compounds of the Invention may be formed by reacting intermediate IVg wherein X is halogen (e.g., chloro) with R₆—OH with heating (Reaction 7):

The Compounds of the Invention wherein Q is CH₂ may be prepared by reacting the Compounds of the Invention wherein Q is C(═O) with a reducing agent, e.g., DIBAL-H or LAH, preferably DIBAL-H.

The Compounds of the Invention wherein Q is C(═S) may be prepared by reacting Compounds of the Invention wherein Q is C(═O) with P₄S₁₀ with P₄S₁₀ in a microwave vial in the presence of a base, e.g., pyridine, and optionally heating the mixture to an elevated temperature, e.g., in a microwave, e.g., to about 150° C.

Compounds of the Invention wherein Q is C(═N(R₂₀)) may be prepared by reacting a compound of the Invention wherein Q is C(═S) with NH₂ (R₂₀) in the presence of HgCl₂ upon heating.

Alternatively, the invention provides methods of making the Compounds of the Invention, for example, comprising reacting intermediate (I)-A with for example R₅—X in a solvent such as DMF and a base such as K₂CO₃, cesium carbonate,

-   -   wherein all the substitutents are as defined previously in any         of Formulae I-VIII; X is a leaving group such as a halogen,         mesylate, or tosylate.

Reactions 1-6 referenced above are useful for preparing intermediates useful for the preparation of compounds of similar core structures, e.g., such as compounds described in WO 2006/133261, WO 2009/075784, PCT/US2009/006442 (or WO 2010/065151) and PCT/US2009/006439 (or WO 2010/065149), the contents of each of which are incorporated by reference in their entirety. Therefore, the invention claims all intermediates disclosed herein, particularly compounds or intermediates of formulae (IVa), (IVB), (IVc), (IVd), (IVe), (IVf) and (IVg). Reactions 1-6 referenced above are not only useful methods for preparing Compounds of the current Invention, but are also useful for preparing compounds as disclosed in WO 2006/133261, WO 2009/075784, PCT/US2009/006442 (or WO 2010/065151) and PCT/US2009/006439 (or WO 2010/065149). Therefore the invention provides a method of making a compound as disclosed in WO 2006/133261, WO 2009/075784, PCT/US2009/006442 (or WO 2010/065151) and PCT/US2009/006439 (or WO 2010/065149), comprising the step(s) as described in any of Reactions 1-6 wherein the intermediates are as defined in the respective applications, for example, as defined in WO 2006/133261 or WO 2009/075784. For example, Intermediate (IVc) as defined in WO 2009/075784 is reacted with an amino alcohol and a coupling reagent such as BOP in the presence of a base such as DBU as described in Reaction 4B to form intermediate of formula (IVe) as defined in WO 2009/075784. Similarly, Intermediate (IVc) as defined in WO 2006/133261 may be reacted with an amino alcohol and a coupling reagent such as BOP in the presence of a base such as DBU as described in Reaction 4B to form intermediate of formula (IVe) as defined in WO 2006/133261. Compound Ia as defined in WO 2006/133261 may be reacted with a halogenating agent such as hexachloroethane, NCS, NBS, I₂ and a base such as LiHMDS in a solvent such as THF at low temperature for several hours as described in Reaction 6. The resulting product may then be reacted with R₆—NH₂ wherein R₆ is as defined in WO 2006/133261 optionally in the presence of a catalyst such as Pd₂ (pda)₃ and a ligand such as xantphos and a base such as potassium carbonate to yield the compound as defined in WO 2006/133261.

Alternatively, Reactions 1-6 may be performed in different order, e.g., wherein Reaction 6 is performed on intermediate (IVb), e.g., reacting intermediate (IVb) with a halogenating agent such as hexachloroethane, NCS, NBS, I₂ and optionally with a base such as LiHMDS in a solvent such as THF at low temperature for several hours. The resulting product may then be reacted with R₆—NH₂ wherein R₆ is as defined in WO 2006/133261 optionally in the presence of a catalyst such as Pd₂ (pda)₃ and a ligand such as xantphos and a base such as potassium carbonate to yield the compound as defined in WO 2006/133261. The resulting product is then deprotected as described in Reaction 2 above. The deprotected product is reacted with an amino alcohol and a coupling reagent such as BOP in the presence of a base such as DBU as described in Reaction 4B followed by the reaction as described in Reaction 5.

Methods of using Compounds of the Invention

The Compounds of the Invention are useful in the treatment of diseases characterized by disruption of or damage to cAMP and cGMP mediated pathways, e.g., as a result of increased expression of PDE1 or decreased expression of cAMP and cGMP due to inhibition or reduced levels of inducers of cyclic nucleotide synthesis, such as dopamine and nitric oxide (NO). By preventing the degradation of cAMP and cGMP by PDE1B, thereby increasing intracellular levels of cAMP and cGMP, the Compounds of the Invention potentiate the activity of cyclic nucleotide synthesis inducers.

The invention provides methods of treatment of any one or more of the following conditions:

-   -   (i) Neurodegenerative diseases, including Parkinson's disease,         restless leg tremors, dyskinesias, Huntington's disease,         Alzheimer's disease, and drug-induced movement disorders;     -   (ii) Mental disorders, including depression, attention deficit         disorder, attention deficit hyperactivity disorder, bipolar         illness, anxiety, sleep disorders, e.g., narcolepsy, cognitive         impairment, dementia, Tourette's syndrome, autism, fragile X         syndrome, psychostimulant withdrawal, and drug addiction;     -   (iii) Circulatory and cardiovascular disorders, including         cerebrovascular disease, stroke, congestive heart disease,         hypertension or pulmonary hypertension, and sexual dysfunction;     -   (iv) Respiratory and inflammatory disorders, including asthma,         chronic obstructive pulmonary disease, and allergic rhinitis, as         well as autoimmune and inflammatory diseases;     -   (v) Any disease or condition characterized by low levels of cAMP         and/or cGMP (or inhibition of cAMP and/or cGMP signaling         pathways) in cells expressing PDE1; and/or     -   (vi) Any disease or condition characterized by reduced dopamine         D1 receptor signaling activity,     -   comprising administering an effective amount of a Compound of         the Invention, e.g., any of Formulae I-VIII or 1.1-1.111, in         free or pharmaceutically acceptable salt form, to a human or         animal patient in need thereof.

In an especially preferred embodiment, the invention provides methods of treatment or prophylaxis for narcolepsy. In this embodiment, PDE 1 Inhibitors may be used as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents. Thus, the invention further comprises a method of treating narcolepsy comprising administering simultaneously, sequentially, or contemporaneously administering therapeutically effective amounts of

-   -   (i) a PDE 1 Inhibitor, e.g., any of Formulae I-VIII or         1.1-1.111, and     -   (ii) a compound to promote wakefulness or regulate sleep, e.g.,         selected from (a) central nervous system stimulants-amphetamines         and amphetamine like compounds, e.g., methylphenidate,         dextroamphetamine, methamphetamine, and pemoline; (b)         modafinil, (c) antidepressants, e.g., tricyclics (including         imipramine, desipramine, clomipramine, and protriptyline) and         selective serotonin reuptake inhibitors (including fluoxetine         and sertraline); and/or (d) gamma hydroxybutyrate (GHB).     -   in free or pharmaceutically acceptable salt form, to a human or         animal patient in need thereof. The Compounds of the Invention         may be used as a sole therapeutic agent or use in combination         for co-administered with another active agent.

In another embodiment, the invention further provides methods of treatment or prophylaxis of a condition which may be alleviated by the enhancement of the progesterone signaling comprising administering an effective amount of a Compound of the Invention, e.g., any of Formulae I-VIII or 1.1-1.111, in free or pharmaceutically acceptable salt form, to a human or animal patient in need thereof. Disease or condition that may be ameliorated by enhancement of progesterone signaling include, but are not limited to, female sexual dysfunction, secondary amenorrhea (e.g., exercise amenorrhoea, anovulation, menopause, menopausal symptoms, hypothyroidism), pre-menstrual syndrome, premature labor, infertility, for example infertility due to repeated miscarriage, irregular menstrual cycles, abnormal uterine bleeding, osteoporosis, autoimmmune disease, multiple sclerosis, prostate enlargement, prostate cancer, and hypothyroidism. For example, by enhancing progesterone signaling, the PDE 1 inhibitors may be used to encourage egg implantation through effects on the lining of uterus, and to help maintain pregnancy in women who are prone to miscarriage due to immune response to pregnancy or low progesterone function. The novel PDE 1 inhibitors, e.g., as described herein, may also be useful to enhance the effectiveness of hormone replacement therapy, e.g., administered in combination with estrogen/estradiol/estriol and/or progesterone/progestins in postmenopausal women, and estrogen-induced endometrial hyperplasia and carcinoma. The methods of the invention are also useful for animal breeding, for example to induce sexual receptivity and/or estrus in a nonhuman female mammal to be bred.

In this embodiment, PDE 1 Inhibitors may be used in the foregoing methods of treatment or prophylaxis as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents, for example in conjunction with hormone replacement therapy. Thus, the invention further comprises a method of treating disorders that may be ameliorated by enhancement of progesterone signaling comprising administering simultaneously, sequentially, or contemporaneously administering therapeutically effective amounts of

-   -   (i) a PDE 1 Inhibitor, e.g., any of Formulae I-VIII or         1.1-1.111, and     -   (ii) a hormone, e.g., selected from estrogen and estrogen         analogues (e.g., estradiol, estriol, estradiol esters) and         progesterone and progesterone analogues (e.g., progestins)         -   in free or pharmaceutically acceptable salt form, to a human             or animal patient in need thereof.

The invention also provides a method for enhancing or potentiating dopamine D1 intracellular signaling activity in a cell or tissue comprising contacting said cell or tissue with an amount of a Compound of the Invention, e.g., any of Formulae I-VIII or 1.1-1.111, sufficient to inhibit PDE1B activity, e.g., PDE1A or PDE1B activity.

The invention also provides a method for treating a PDE1-related, especially PDE1B-related disorder, a dopamine D1 receptor intracellular signaling pathway disorder, or disorders that may be alleviated by the enhancement of the progesterone signaling pathway in a patient in need thereof comprising administering to the patient an effective amount of a Compound of the Invention, e.g., any of Formulae I-VIII or 1.1-1.111, in that inhibits PDE1B, wherein PDE1B activity modulates phosphorylation of DARPP-32 and/or the GluR1 AMPA receptor.

In another aspect, the invention also provides a method for the treatment for glaucoma or elevated intraocular pressure comprising topical administration of a therapeutically effective amount of a phosphodiesterase type I (PDE1) Inhibitor of the Invention, in free or pharmaceutically acceptable salt form, in an ophthalmically compatible carrier to the eye of a patient in need thereof. However, treatment may alternatively include a systemic therapy. Systemic therapy includes treatment that can directly reach the bloodstream, or oral methods of administration, for example.

The invention further provides a pharmaceutical composition for topical ophthalmic use comprising a PDE1 inhibitor; for example an ophthalmic solution, suspension, cream or ointment comprising a PDE1 Inhibitor of the Invention, in free or ophthalmologically acceptable salt form, in combination or association with an ophthalmologically acceptable diluent or carrier.

Optionally, the PDE1 inhibitor may be administered sequentially or simultaneously with a second drug useful for treatment of glaucoma or elevated intraocular pressure. Where two active agents are administered, the therapeutically effective amount of each agent may be below the amount needed for activity as monotherapy. Accordingly, a subthreshold amount (i.e., an amount below the level necessary for efficacy as monotherapy) may be considered therapeutically effective and also may also be referred alternatively as an effective amount. Indeed, an advantage of administering different agents with different mechanisms of action and different side effect profiles may be to reduce the dosage and side effects of either or both agents, as well as to enhance or potentiate their activity as monotherapy.

The invention thus provides the method of treatment of a condition selected from glaucoma and elevated intraocular pressure comprising administering to a patient in need thereof an effective amount, e.g., a subthreshold amount, of an agent known to lower intraocular pressure concomitantly, simultaneously or sequentially with an effective amount, e.g., a subthreshold amount, of a PDE1 Inhibitor of the Invention, in free or pharmaceutically acceptable salt form, such that amount of the agent known to lower intraocular pressure and the amount of the PDE1 inhibitor in combination are effective to treat the condition.

In one embodiment, one or both of the agents are administered topically to the eye. Thus the invention provides a method of reducing the side effects of treatment of glaucoma or elevated intraocular pressure by administering a reduced dose of an agent known to lower intraocular pressure concomitantly, simultaneously or sequentially with an effective amount of a PDE1 inhibitor. However, methods other than topical administration, such as systemic therapeutic administration, may also be utilized.

The optional additional agent or agents for use in combination with a PDE1 inhibitor may, for example, be selected from the existing drugs comprise typically of instillation of a prostaglandin, pilocarpine, epinephrine, or topical beta-blocker treatment, e.g. with timolol, as well as systemically administered inhibitors of carbonic anhydrase, e.g. acetazolamide. Cholinesterase inhibitors such as physostigmine and echothiopate may also be employed and have an effect similar to that of pilocarpine. Drugs currently used to treat glaucoma thus include, e.g.,

-   -   1. Prostaglandin analogs such as latanoprost (Xalatan),         bimatoprost (Lumigan) and travoprost (Travatan), which increase         uveoscleral outflow of aqueous humor. Bimatoprost also increases         trabecular outflow.     -   2. Topical beta-adrenergic receptor antagonists such as timolol,         levobunolol (Betagan), and betaxolol, which decrease aqueous         humor production by the ciliary body.     -   3. Alpha₂-adrenergic agonists such as brimonidine (Alphagan),         which work by a dual mechanism, decreasing aqueous production         and increasing uveo-scleral outflow.     -   4. Less-selective sympathomimetics like epinephrine and         dipivefrin (Propine) increase outflow of aqueous humor through         trabecular meshwork and possibly through uveoscleral outflow         pathway, probably by a beta₂-agonist action.     -   5. Miotic agents (parasympathomimetics) like pilocarpine work by         contraction of the ciliary muscle, tightening the trabecular         meshwork and allowing increased outflow of the aqueous humour.     -   6. Carbonic anhydrase inhibitors like dorzolamide (Trusopt),         brinzolamide (Azopt), acetazolamide (Diamox) lower secretion of         aqueous humor by inhibiting carbonic anhydrase in the ciliary         body.     -   7. Physostigmine is also used to treat glaucoma and delayed         gastric emptying.

For example, the invention provides pharmaceutical compositions comprising a PDE1 Inhibitor of the Invention and an agent selected from (i) the prostanoids, unoprostone, latanoprost, travoprost, or bimatoprost; (ii) an alpha adrenergic agonist such as brimonidine, apraclonidine, or dipivefrin and (iii) a muscarinic agonist, such as pilocarpine. For example, the invention provides ophthalmic formulations comprising a PDE-1 Inhibitor of the Invention together with bimatoprost, abrimonidine, brimonidine, timolol, or combinations thereof, in free or ophthamalogically acceptable salt form, in combination or association with an ophthamologically acceptable diluent or carrier. In addition to selecting a combination, however, a person of ordinary skill in the art can select an appropriate selective receptor subtype agonist or antagonist. For example, for alpha adrenergic agonist, one can select an agonist selective for an alpha 1 adrenergic receptor, or an agonist selective for an alpha₂ adrenergic receptor such as brimonidine, for example. For a beta-adrenergic receptor antagonist, one can select an antagonist selective for either β₁, or β₂, or β₃, depending on the appropriate therapeutic application. One can also select a muscarinic agonist selective for a particular receptor subtype such as M₁-M₅.

The PDE 1 inhibitor may be administered in the form of an ophthalmic composition, which includes an ophthalmic solution, cream or ointment. The ophthalmic composition may additionally include an intraocular-pressure lowering agent.

In yet another example, the PDE-1 Inhibitors disclosed may be combined with a subthreshold amount of an intraocular pressure-lowering agent which may be a bimatoprost ophthalmic solution, a brimonidine tartrate ophthalmic solution, or brimonidine tartrate/timolol maleate ophthalmic solution.

In addition to the above-mentioned methods, it has also been surprisingly discovered that PDE1 inhibitors are useful to treat psychosis, for example, any conditions characterized by psychotic symptoms such as hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, and mania, such as in acute manic episodes and bipolar disorder. Without intending to be bound by any theory, it is believed that typical and atypical antipsychotic drugs such as clozapine primarily have their antagonistic activity at the dopamine D2 receptor. PDE1 inhibitors, however, primarily act to enhance signaling at the dopamine D1 receptor. By enhancing D1 receptor signaling, PDE1 inhibitors can increase NMDA receptor function in various brain regions, for example in nucleus accumbens neurons and in the prefrontal cortex. This enhancement of function may be seen for example in NMDA receptors containing the NR2B subunit, and may occur e.g., via activation of the Src and protein kinase A family of kinases.

Therefore, the invention provides a new method for the treatment of psychosis, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, and mania, such as in acute manic episodes and bipolar disorder, comprising administering a therapeutically effective amount of a phosphodiesterase-1 (PDE1) Inhibitor of the Invention, in free or pharmaceutically acceptable salt form, to a patient in need thereof.

PDE 1 Inhibitors may be used in the foregoing methods of treatment prophylaxis as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents. Thus, the invention further comprises a method of treating psychosis, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, or mania, comprising administering simultaneously, sequentially, or contemporaneously administering therapeutically effective amounts of:

-   -   (i) a PDE 1 Inhibitor of the invention, in free or         pharmaceutically acceptable salt form; and     -   (ii) an antipsychotic, e.g.,         -   Typical antipsychotics, e.g.,             -   Butyrophenones, e.g. Haloperidol (Haldol, Serenace),                 Droperidol (Droleptan);             -   Phenothiazines, e.g., Chlorpromazine (Thorazine,                 Largactil), Fluphenazine (Prolixin), Perphenazine                 (Trilafon), Prochlorperazine (Compazine), Thioridazine                 (Mellaril, Melleril), Trifluoperazine (Stelazine),                 Mesoridazine, Periciazine, Promazine, Triflupromazine                 (Vesprin), Levomepromazine (Nozinan), Promethazine                 (Phenergan), Pimozide (Orap);             -   Thioxanthenes, e.g., Chlorprothixene, Flupenthixol                 (Depixol, Fluanxol), Thiothixene (Navane),                 Zuclopenthixol (Clopixol, Acuphase);         -   Atypical antipsychotics, e.g.,             -   Clozapine (Clozaril), Olanzapine (Zyprexa), Risperidone                 (Risperdal), Quetiapine (Seroquel), Ziprasidone                 (Geodon), Amisulpride (Solian), Paliperidone (Invega),                 Aripiprazole (Abilify), Bifeprunox; norclozapine,             -   in free or pharmaceutically acceptable salt form, to a                 patient in need thereof.

In a particular embodiment, the Compounds of the Invention are particularly useful for the treatment or prophylaxis of schizophrenia.

Compounds of the Invention, in free or pharmaceutically acceptable salt form, are particularly useful for the treatment of Parkinson's disease, schizophrenia, narcolepsy, glaucoma and female sexual dysfunction.

In still another aspect, the invention provides a method of lengthening or enhancing growth of the eyelashes by administering an effective amount of a prostaglandin analogue, e.g., bimatoprost, concomitantly, simultaneously or sequentially with an effective amount of a PDE1 inhibitor of the Invention, in free or pharmaceutically acceptable salt form, to the eye of a patient in need thereof.

In yet another aspect, the invention provides a method for the treatment or prophylaxis of traumatic brain injury comprising administering a therapeutically effective amount of a PDE1 inhibitor of the invention, in free or pharmaceutically acceptable salt form, to a patient in need thereof. Traumatic brain injury (TBI) encompasses primary injury as well as secondary injury, including both focal and diffuse brain injuries. Secondary injuries are multiple, parallel, interacting and interdependent cascades of biological reactions arising from discrete subcellular processes (e.g., toxicity due to reactive oxygen species, overstimulation of glutamate receptors, excessive influx of calcium and inflammatory upregulation) which are caused or exacerbated by the inflammatory response and progress after the initial (primary) injury. Abnormal calcium homeostasis is believed to be a critical component of the progression of secondary injury in both grey and white matter. For a review of TBI, see Park et al., CMAJ (2008) 178(9):1163-1170, the contents of which are incorporated herein in their entirety. Studies have shown that the cAMP-PKA signaling cascade is downregulated after TBI and treatment of PDE IV inhibitors such as rolipram to raise or restore cAMP level improves histopathological outcome and decreases inflammation after TBI. As Compounds of the present invention is a PDE1 inhibitor, it is believed that these compounds are also useful for the treatment of TBI, e.g., by restoring cAMP level and/or calcium homeostasis after traumatic brain injury.

The present invention also provides

-   -   (i) a Compound of the Invention, e.g., any of Formulae I-VIII or         1.1-1.111, as hereinbefore described, in free or         pharmaceutically acceptable salt form for example for use in any         method or in the treatment of any disease or condition as         hereinbefore set forth,     -   (ii) the use of a Compound of the Invention, e.g any of Formulae         I-VIII or 1.1-1.111, as hereinbefore described, in free or         pharmaceutically acceptable salt form, in the manufacture of a         medicament for treating any disease or condition as hereinbefore         set forth,     -   (iii) a pharmaceutical composition comprising a Compound of the         Invention, e.g., any of Formulae I-VIII or 1.1-1.111, as         hereinbefore described, in free or pharmaceutically acceptable         salt form, in combination or association with a pharmaceutically         acceptable diluent or carrier, and     -   (iv) a pharmaceutical composition comprising a Compound of the         Invention, e.g., any of Formulae I-VIII or 1.1-1.111, as         hereinbefore described, in free or pharmaceutically acceptable         salt form, in combination or association with a pharmaceutically         acceptable diluent or carrier for use in the treatment of any         disease or condition as hereinbefore set forth.

Therefore, the invention provides use of a Compound of the Invention, e.g., any of Formulae I-VIII or 1.1-1.111, as hereinbefore described, in free or pharmaceutically acceptable salt form, or a Compound of the Invention in a pharmaceutical composition form, (the manufacture of a medicament) for the treatment or prophylactic treatment of the following diseases: Parkinson's disease, restless leg tremors, dyskinesias, Huntington's disease, Alzheimer's disease, and drug-induced movement disorders; depression, attention deficit disorder, attention deficit hyperactivity disorder, bipolar illness, anxiety, sleep disorder, narcolepsy, cognitive impairment, dementia, Tourette's syndrome, autism, fragile X syndrome, psychostimulant withdrawal, and/or drug addiction; cerebrovascular disease, stroke, congestive heart disease, hypertension or pulmonary hypertension, and/or sexual dysfunction; asthma, chronic obstructive pulmonary disease, and/or allergic rhinitis, as well as autoimmune and inflammatory diseases; and/or female sexual dysfunction, exercise amenorrhoea, anovulation, menopause, menopausal symptoms, hypothyroidism, pre-menstrual syndrome, premature labor, infertility, irregular menstrual cycles, abnormal uterine bleeding, osteoporosis, multiple sclerosis, prostate enlargement, prostate cancer, hypothyroidism, estrogen-induced endometrial hyperplasia or carcinoma; and/or any disease or condition characterized by low levels of cAMP and/or cGMP (or inhibition of cAMP and/or cGMP signaling pathways) in cells expressing PDE1, and/or by reduced dopamine D1 receptor signaling activity; and/or any disease or condition that may be ameliorated by the enhancement of progesterone signaling.

The invention also provides use of a Compound of the Invention, in free or pharmaceutically acceptable salt form, (the manufacture of a medicament) for the treatment or prophylactic treatment of:

-   -   a) glaucoma or elevated intraocular pressure,     -   b) psychosis, for example, any conditions characterized by         psychotic symptoms such as hallucinations, paranoid or bizarre         delusions, or disorganized speech and thinking, e.g.,         schizophrenia, schizoaffective disorder, schizophreniform         disorder, psychotic disorder, delusional disorder, and mania,         such as in acute manic episodes and bipolar disorder, or     -   c) traumatic brain injury.

The phrase “Compounds of the Invention” or “PDE 1 inhibitors of the Invention” encompasses any and all of the compounds disclosed herewith, e.g., an optionally substituted:

-   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine, -   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, -   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, -   4,5,7,8-tetrahydro-(1H or     2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, -   4,5,7,8,9-pentahydro-(1H or     2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine, -   any of Formulae I-VIII or 1.1-1.111,     -   in free or (pharmaceutically) salt form.

The words “treatment” and “treating” are to be understood accordingly as embracing prophylaxis and treatment or amelioration of symptoms of disease as well as treatment of the cause of the disease.

For methods of treatment, the word “effective amount” is intended to encompass a therapeutically effective amount to treat a specific disease or disorder.

The term “pulmonary hypertension” is intended to encompass pulmonary arterial hypertension.

The term “patient” include human or non-human (i.e., animal) patient. In particular embodiment, the invention encompasses both human and nonhuman. In another embodiment, the invention encompasses nonhuman. In other embodiment, the term encompasses human.

The term “comprising” as used in this disclosure is intended to be open-ended and does not exclude additional, unrecited elements or method steps.

Compounds of the Invention are in particular useful for the treatment of Parkinson's disease, narcolepsy and female sexual dysfunction.

Compounds of the Invention, in free or pharmaceutically acceptable salt form, may be used as a sole therapeutic agent, but may also be used in combination or for co-administration with other active agents. For example, as Compounds of the Invention potentiate the activity of D1 agonists, such as dopamine, they may be simultaneously, sequentially, or contemporaneously administered with conventional dopaminergic medications, such as levodopa and levodopa adjuncts (carbidopa, COMT inhibitors, MAO-B inhibitors), dopamine agonists, and anticholinergics, e.g., in the treatment of a patient having Parkinson's disease. In addition, the novel PDE 1 inhibitors, e.g., as described herein, may also be administered in combination with estrogen/estradiol/estriol and/or progesterone/progestins to enhance the effectiveness of hormone replacement therapy or treatment of estrogen-induced endometrial hyperplasia or carcinoma.

Dosages employed in practicing the present invention will of course vary depending, e.g. on the particular disease or condition to be treated, the particular Compound of the Invention used, the mode of administration, and the therapy desired. Compounds of the Invention may be administered by any suitable route, including orally, parenterally, transdermally, or by inhalation, but are preferably administered orally. In general, satisfactory results, e.g. for the treatment of diseases as hereinbefore set forth are indicated to be obtained on oral administration at dosages of the order from about 0.01 to 2.0 mg/kg. In larger mammals, for example humans, an indicated daily dosage for oral administration will accordingly be in the range of from about 0.75 to 150 mg, conveniently administered once, or in divided doses 2 to 4 times, daily or in sustained release form. Unit dosage forms for oral administration thus for example may comprise from about 0.2 to 75 or 150 mg, e.g. from about 0.2 or 2.0 to 50, 75 or 100 mg of a Compound of the Invention, together with a pharmaceutically acceptable diluent or carrier therefor.

Pharmaceutical compositions comprising Compounds of the Invention may be prepared using conventional diluents or excipients and techniques known in the galenic art. Thus oral dosage forms may include tablets, capsules, solutions, suspensions and the like.

EXAMPLES

The synthetic methods for various Compounds of the Present Invention are illustrated below. Other compounds of the Invention and their salts may be made using the methods as similarly described below and/or by methods similar to those generally described in the detailed description and by methods known in the chemical art.

Example 1 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-3-phenoxy-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

(a) 2-(4-(1H-pyrazol-1-yl)benzyl)-7-(4-methoxybenzyl)-5-methyl-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione

A suspension of 7-(4-methoxybenzyl)-5-methyl-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione (667 mg, 2.33 mmol), 1-(4-(bromomethyl)phenyl)-1H-pyrazole (552 mg, 2.33 mmol) and K₂CO₃ (644 mg, 4.66 mmol) in DMF (20 mL) is stirred at room temperature overnight. Solvent is removed under reduced pressure. The obtained residue is treated with methylene chloride (400 mL), and then washed with water three times. The organic phase is evaporated to dryness to give 1.0 g of crude product, which is used in the next step without further purification. MS (ESI) m/z 443.2 [M+H]⁺.

(b) 2-(4-(1H-pyrazol-1-yl)benzyl)-5-methyl-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione

TFA (3.0 mL) is added into a suspension of 2-(4-(1H-pyrazol-1-yl)benzyl)-7-(4-methoxybenzyl)-5-methyl-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione (1.0 g, 2.3 mmol) in methylene chloride (6 mL) to give a tan solution, and then TFMSA (0.85 mL) is added. The reaction mixture is stirred at room temperature overnight, and then diluted with 100 mL of methylene chloride, followed by adding 50 mL of water to precipitate product out of solution. After filtration, the obtained solids are washed with water twice, and then dried under vacuum to give the first crop of crude product. The organic phase in the filtrate is washed with water twice, and then evaporated to remove solvents to the second crop of crude product. The obtained crude product is combined (0.94 g in total) and is used in the next step without further purification. MS (ESI) m/z 323.1 [M+H]⁺.

(c) 2-(4-(1H-pyrazol-1-yl)benzyl)-6-((1R,2R)-2-hydroxycyclopentylamino)-5-methyl-2H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

DBU (1.2 mL, 7.9 mmol) is added into a suspension of crude 2-(4-(1H-pyrazol-1-yl)benzyl)-5-methyl-2H-pyrazolo[3,4-d]pyrimidine-4,6(5H,7H)-dione TFMSA salt (620 mg, 1.3 mmol) and BOP (1.7 g, 3.9 mmol) in THF (12 mL) to give a yellow solution. The mixture is stirred at room temperature for 5 min, and then (1R,2R)-2-aminocyclopentanol hydrochloride (542 mg, 3.9 mmol) is added. The reaction mixture is stirred at room temperature for 4 hours. After removal of solvent, the residue is treated with methylene chloride, and then washed with saturated NaHCO₃ aqueous solution three times. The organic phase is evaporated to dryness to give 2.1 g salt-containing crude product, which is used in the next step without further purification. MS (ESI) m/z 406.2 [M+H]⁺.

(d) (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

Thionyl chloride (180 kL, 2.47 mmol) is added dropwise to a solution of crude 2-(4-(1H-pyrazol-1-yl)benzyl)-6-((1R,2R)-2-hydroxycyclopentylamino)-5-methyl-2H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (2.0 g, 4.9 mmol) in DMF (10 mL). The reaction mixture is stirred at room temperature for 20 min. DMF is removed under reduced pressure. The obtained residue is treated with methylene chloride (200 mL), and then washed with 5% NaHCO₃ aqueous solution three times (3×80 mL). The organic phase is evaporated to dryness to give 1.1 g crude product, which is used in the next step without further purification. MS (ESI) m/z 388.2 [M+H]⁺.

(e) (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-chloro-5-methyl-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

1.0M LiHMDS (4.25 mL, 4.25 mml) in THF is added dropwise into a solution of crude (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one (1.1 g) and hexachloroethane (403 mg, 1.7 mmol) in methylene chloride (20 mL). The reaction mixture is stirred at room temperature for 20 min, and then diluted with methylene chloride (130 mL), followed by washing with water four times (4×50 mL). The organic phase is evaporated to dryness to give 754 mg of crude product with 84% purity, which is used in the next step without further purification. MS (ESI) m/z 422.2 [M+H]⁺.

(f) (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-3-phenoxy-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

Crude (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-chloro-5-methyl-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one (50 mg), phenol (45 mg, 0.47 mmol) and Cs₂CO₃ (77 mg, 0.24 mmol) are placed in a microwave vial, and then dioxane (1 mL) is added. The vial is sealed and heated in a Biotage microwave instrument at 130° C. for 40 min. The reaction mixture is then purified with a semi-preparative HPLC to give 11 mg of product as off-white solid (purity: 97%). MS (ESI) m/z 480.2 [M+H]⁺.

Example 2 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-(4-fluorophenoxy)-5-methyl-2-(4-(pyridin2-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to example 1 wherein 2-(4-(chloromethyl)phenyl)pyridine is added in step (a) instead of 1-(4-(bromomethyl)phenyl)-1H-pyrazole; and 4-fluorophenol is added in step (f) instead of phenol. MS (ESI) m/z 509.2 [M+H]⁺

Example 3 7,8-dihydro-5,7,7-trimethyl-3-phenoxy-2-(4-(6-Fluoro-pyridin-2-yl)-benzyl)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to example 1 wherein 2-(4-(chloromethyl)phenyl)-6-fluoropyridine is added in step (a) instead of 1-(4-(bromomethyl)phenyl)-1H-pyrazole; and 2-amino-2-methylpropan-1-ol is added in step (c) instead of (1R,2R)-2-aminocyclopentanol hydrochloride. MS (ESI) m/z 497.2 [M+H]⁺

Example 4 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-5-methyl-3-(4-fluorophenoxy)-2-(4-(1H-pyrazol-1-yl)benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to example 1 wherein 4-fluorophenol is added in step (f) instead of phenol. MS (ESI) m/z 498.3 [M+H]

Example 5 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-(cyclohexyloxy)-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

(6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-chloro-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one (25 mg, 0.055 mmol), cyclohexanol (0.5 mL) and Cs₂CO₃ (27 mg, 0.083 mmol) are placed in a microwave vial. The vial is sealed and heated in a Biotage microwave instrument at 140° C. for an hour. The reaction mixture is then purified with a semi-preparative HPLC to give 14 mg of product as white solids (purity: 98%). MS (ESI) m/z 515.2 [M+H]⁺.

Example 6 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-(cyclopentyloxy)-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to Example 5 wherein cyclopentanol is added instead of cyclohexanol. MS (ESI) m/z 501.3 [M+H]⁺

Example 7 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-isobutoxy-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to Example 5 wherein 2-methylpropan-1-ol is added instead of cyclohexanol. MS (ESI) m/z 489.3 [M+H]⁺

Example 8 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-isopropoxy-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to Example 5 wherein propan-2-ol is added instead of cyclohexanol. MS (ESI) m/z 475.2 [M+H]⁺

Example 9 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-phenoxy-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

(6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-chloro-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one (26 mg, 0.058 mmol), phenol (10.8 mg, 0.12 mmol) and K₂CO₃ (24 mg, 0.17 mmol) are placed in a microwave vial, and then dioxane (0.5 mL) is added. The vial is sealed and heated in a Biotage microwave instrument at 150° C. for three hours. The reaction mixture is then purified with a semi-preparative HPLC to give 21 mg of product as white solids (purity: 98.6%). MS (ESI) m/z 509.2 [M+H]⁺.

Example 10 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-(4-fluorophenoxy)-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to Example 9 wherein 4-fluorophenol is added instead of phenol. MS (ESI) m/z 527.2 [M+H]⁺

Example 11 (6aR,9aS)-5,6a,7,8,9,9a-hexahydro-3-(3-chlorophenoxy)-5-methyl-2-(4-(6-fluoro-pyridin-2-yl)-benzyl)-cyclopent[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(2H)-one

The synthesis method is analogous to Example 9 wherein 3-chlorophenol is added instead of phenol. MS (ESI) m/z 543.2 [M+H]⁺

Example 12 Measurement of PDE1B Inhibition In Vitro Using IMAP Phosphodiesterase Assay Kit

Phosphodiesterase 1B (PDE1B) is a calcium/calmodulin dependent phosphodiesterase enzyme that converts cyclic guanosine monophosphate (cGMP) to 5′-guanosine monophosphate (5′-GMP). PDE1B can also convert a modified cGMP substrate, such as the fluorescent molecule cGMP-fluorescein, to the corresponding GMP-fluorescein. The generation of GMP-fluorescein from cGMP-fluorescein can be quantitated, using, for example, the IMAP (Molecular Devices, Sunnyvale, Calif.) immobilized-metal affinity particle reagent.

Briefly, the IMAP reagent binds with high affinity to the free 5′-phosphate that is found in GMP-fluorescein and not in cGMP-fluorescein. The resulting GMP-fluorescein—IMAP complex is large relative to cGMP-fluorescein. Small fluorophores that are bound up in a large, slowly tumbling, complex can be distinguished from unbound fluorophores, because the photons emitted as they fluoresce retain the same polarity as the photons used to excite the fluorescence.

In the phosphodiesterase assay, cGMP-fluorescein, which cannot be bound to IMAP, and therefore retains little fluorescence polarization, is converted to GMP-fluorescein, which, when bound to IMAP, yields a large increase in fluorescence polarization (Δmp). Inhibition of phosphodiesterase, therefore, is detected as a decrease in Δmp.

Enzyme Assay

-   -   Materials: All chemicals are available from Sigma-Aldrich (St.         Louis, Mo.) except for IMAP reagents (reaction buffer, binding         buffer, FL-GMP and IMAP beads), which are available from         Molecular Devices (Sunnyvale, Calif.).     -   Assay: 3′,5′-cyclic-nucleotide-specific bovine brain         phosphodiesterase (Sigma, St. Louis, Mo.) is reconstituted with         50% glycerol to 2.5 U/ml. One unit of enzyme will hydrolyze 1.0         μmole of 3′,5′-cAMP to 5′-AMP per min at pH 7.5 at 30° C. One         part enzyme is added to 1999 parts reaction buffer (30 μM CaCl₂,         10 U/ml of calmodulin (Sigma P2277), 10 mM Tris-HCl pH 7.2, 10         mM MgCl₂, 0.1% BSA, 0.05% NaN₃) to yield a final concentration         of 1.25 mU/ml. 99 μl of diluted enzyme solution is added into         each well in a flat bottom 96-well polystyrene plate to which 1         μl of test compound dissolved in 100% DMSO is added. Selected         Compounds of the Invention are mixed and pre-incubated with the         enzyme for 10 min at room temperature.

The FL-GMP conversion reaction is initiated by combining 4 parts enzyme and inhibitor mix with 1 part substrate solution (0.225 μM) in a 384-well microtiter plate. The reaction is incubated in dark at room temperature for 15 min. The reaction is halted by addition of 60 μl of binding reagent (1:400 dilution of IMAP beads in binding buffer supplemented with 1:1800 dilution of antifoam) to each well of the 384-well plate. The plate is incubated at room temperature for 1 hour to allow IMAP binding to proceed to completion, and then placed in an Envision multimode microplate reader (PerkinElmer, Shelton, Conn.) to measure the fluorescence polarization (Δmp).

A decrease in GMP concentration, measured as decreased Δmp, is indicative of inhibition of PDE activity. IC₅₀ values are determined by measuring enzyme activity in the presence of 8 to 16 concentrations of compound ranging from 0.0037 nM to 80,000 nM and then plotting drug concentration versus AmP, which allows IC₅₀ values to be estimated using nonlinear regression software (XLFit; IDBS, Cambridge, Mass.).

The Compounds of the Invention may be selected and tested in an assay as described or similarly described herein for PDE1 inhibitory activity. The exemplified compounds of the invention generally have IC₅₀ values of less than or equal to 100 nM, some less than 10 nM, some less than 1 nM, against PDE1A and/or PDE1B.

Example 13

Pde1 Inhibitor Effect on Sexual Response in Female Rats

The effect of PDE1 inhibitors on Lordosis Response in female rats may be measured as described in Mani, et al., Science (2000) 287: 1053. Ovariectomized and cannulated wild-type rats are primed with 2 μg estrogen followed 24 hours later by intracerebroventricular (icy) injection of progesterone (2 μg), PDE1 inhibitors of the present invention (0.1 mg, 1.0 mg or 2.5 mg) or sesame oil vehicle (control). The rats may be tested for lordosis response in the presence of male rats. Lordosis response is quantified by the lordosis quotient (LQ=number of lordosis/10 mounts×100). 

1. A compound selected from optionally substituted 3-oxy substituted 4,5,7,8-tetrahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine or 4,5,7,8,9-pentahydro-(optionally 4-oxo, 4-thioxo or 4-imino)-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine compounds, in free or salt form.
 2. The compound according to claim 1, wherein said compound is selected from any one of the following: optionally substituted 3-oxy substituted 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine, 3-oxy substituted 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, 3-oxy substituted 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, 3-oxy substituted 4,5,7,8-tetrahydro-(1H or 2H)-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine, 3-oxy substituted 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine, 3-oxy substituted 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-one, 3-oxy substituted 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-thione, and 3-oxy substituted 4,5,7,8,9-pentahydro-(1H or 2H)-pyrimido[1,2-a]pyrazolo[4,3-e]pyrimidine-4(5H)-imine, in free or salt form.
 3. The compound according to claim 1, wherein said compound is a compound of Formula I:

wherein (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂; (ii) L is a —O—; (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₄ is H or C₁₋₄alkyl (e.g., methyl or isopropyl) and R₂ and R₃ are, independently: H, C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂ is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl), aryl, heteroaryl, (optionally hetero)arylC₁₋₆alkyl, or  R₂ and R₃ together with the carbon to which they are attached form a 3- to 6-membered ring; or  R₂ is H and R₃ and R₄ together form a di-, tri- or tetra-methylene bridge,  (pref. wherein the R₃ and R₄ together have the cis configuration, e.g., where the carbons carrying R₃ and R₄ have the R and S configurations, respectively); (v) R₅ is a) -D-E-F, wherein: D is a single bond, C₁₋₄alkylene (e.g., methylene, ethylene or prop-2-yn-1-ylene) or —C(═O)—; E is a single bond, C₁₋₄alkylene (e.g., methylene, —C≡C—), arylene (e.g., phenylene), arylC₁₋₄alkylene (e.g., benzylene) or heteroarylene (e.g., pyridylene); and F is H, aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, diazolyl, triazolyl, for example, pyrid-2-yl, imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl), halo (e.g., F, Br, Cl), C₁₋₄alkyl (e.g., methyl), haloC₁₋₄alkyl (e.g., trifluoromethyl), haloC₁₋₄alkoxy, C₁₋₄alkoxy (e.g., methoxy), —C(O)—RIS, —N(R₁₆)(R₁₇), —S(O)₂R₂₁, C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example, pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl), piperidinyl (e.g., piperidin-2-yl), tetrahydro-2H-pyran-4-yl or morpholinyl); wherein D, E and F are independently and optionally substituted with one or more group selected from: halo (e.g., F, Cl or Br), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl), haloC₁₋₄alkyl (e.g., trifluoromethyl), and C₁₋₄alkoxy (methoxy), for example, F is heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl or oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl) optionally substituted with one or more group selected from halo and C₁₋₆alkyl (e.g., 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl), or F is aryl, e.g., phenyl, optionally substituted with one or more halo (e.g., 4-fluorophenyl); or F is a C₃₋₇heterocycloalkyl (e.g., pyrrolidinyl) optionally substituted with a C₁₋₆alkyl (e.g., 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl); b) a substituted heteroarylC₁₋₄alkyl, e.g., substituted with haloC₁₋₄alkyl; or c) attached to one of the nitrogen atoms on the pyrazolo portion of Formula I and is a moiety of Formula A

wherein X, Y and Z are, independently, N or C, and R₈, R₉, R₁₁ and R₁₂ are independently H, halogen (e.g., Cl or F), —C₁₋₄alkyl-N(R₂₂)(R₂₃) (e.g., aminomethyl, isopropylaminomethyl or isobutylaminomethyl), or —C₁₋₄alkyl-heterC₃₋₈cycloalkyl (e.g., pyrrolidin-1-ylmethyl), and R₁₀ is: hydrogen, halogen (chloro or fluoro), C₁₋₄alkyl, haloC₁₋₄alkyl (e.g., trifluoromethyl), haloC₁₋₄alkoxy (e.g., trifluoromethoxy), C₁₋₄alkoxy, C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), C₁₋₄haloalkyl (e.g., trifluoromethyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl or oxodiazolyl (e.g., 1,2,4-oxodiazol-3-yl), arylcarbonyl (e.g., benzoyl), C₁₋₄alkylsulfonyl (e.g., methylsulfonyl), aminosulfonyl (e.g., —S(O)₂—N(R₁₈)(R₁₉), heteroarylcarbonyl, C₁₋₄alkylcarbonyl (e.g., methylcarbonyl), C₁₋₄alkoxycarbonyl, (e.g., —C(O)OCH₃), —C(O)OH, haloC₁₋₄alkoxycarbony (e.g., trifluoromethylcarbonyl), —C(O)N(R₁₈)(R₁₉), or —C₁₋₄alkyl-N(R₁₈)(R₁₉) (e.g., methylaminomethyl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more group selected from halo (e.g., F or Cl), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl), C₁₋₄alkoxy, C₁₋₄haloalkyl (e.g., trifluoromethyl) and —SH; For example, R₁₀ is phenyl, pyridyl, pyrazolyl, piperidinyl, pyrrolidinyl oxadiazolyl pyrimidinyl, optionally substituted with one or more group selected from halo (e.g., F or Cl), C₁₋₄alkyl (e.g., methyl or prop-2-yn-1-yl), C₁₋₄alkoxy, C₁₋₄haloalkyl (e.g., trifluoromethyl) and —SH, e.g. optionally substituted with halo or C₁₋₄alkyl, for example R₁₀ is 1-methylpiperidin-2-yl, piperidin-2-yl, 1-ethylpiperidin-2-yl, 1-methylpyrrolidin-2-yl, 1-methylimidazol-2-yl, halopyridyl (for example 6-fluoropyrid-2-yl), provided that when X, Y, or Z is nitrogen, R₈, R₉, or R₁₀, respectively, is not present; (vi) R₆ is C₁₋₄alkyl (e.g., isopropyl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), or arylC₁₋₄alkyl (e.g., benzyl), wherein the aryl or heteroaryl is optionally substituted with one or more group selected from halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy and C₃₋₈cycloalkyl, for example, R₆ is 3-chlorophenyl or 4-fluorophenyl, (vii) n=0 or 1; (viii) when n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃ and R₁₄, are, independently, H, C₁₋₄alkyl, aryl, heteroaryl, (optionally hetero)arylC₁₋₄alkoxy or (optionally hetero)arylC₁₋₄alkyl or R₁₃ or R₁₄ can form a di-, tri- or tetramethylene bridge with R₂ or R₄; (ix) R₁₅ is C₁₋₄alkyl (e.g., methyl), haloC₁₋₄alkyl (e.g., trifluoromethyl), —OH, —OC₁₋₄alkyl (e.g., —OCH₃), aryl (e.g., phenyl) or —N(R₁₆)(R₁₇); (x) R₁₆ and R₁₇ are independently H or C₁₋₄alkyl; (xi) R₁₈ and R₁₉ are independently H, C₁₋₄alky, C₃₋₈cycloalkyl, heteroC₃₋₈cycloalkyl, aryl (e.g., phenyl), or heteroaryl, wherein said aryl or heteroaryl is optionally substituted with one or more group selected from: halo (e.g., fluorophenyl, e.g., 4-fluorophenyl), hydroxy (e.g., hydroxyphenyl, e.g., 4-hydroxyphenyl or 2-hydroxyphenyl), C₁₋₆alkyl, haloC₁₋₆alkyl, C₁₋₆alkoxy, aryl, heteroaryl, and C₃₋₈cycloalkyl; (xii) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl; (xiii) R₂₁ is C₁₋₆alkyl (e.g., methyl) or —N(R₈)(R₁₉); (xiv) R₂₂ and R₂₃ are independently H or C₁₋₄alkyl (e.g., methyl), in free or salt form.
 4. The compound according to claim 1, wherein said compound is selected form any one of the following: A) a Compound of Formula II:

wherein (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂; (ii) L is a —O—; (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₄ is H or C₁₋₄alkyl (e.g., methyl or isopropyl) and R₂ and R₃ are, independently: H, C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂ is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl), aryl, heteroaryl, (optionally hetero)arylC₁₋₆alkoxy, or (optionally hetero)arylC₁₋₆alkyl, or  R₂ and R₃ together with the carbon to which they are attached form a 3- to 6-membered ring; or  R₂ is H and R₃ and R₄ together form a di-, tri- or tetramethylene bridge  (pref. wherein the R₃ and R₄ together have the cis configuration, e.g., where the carbons carrying R₃ and R₄ have the R and S configurations, respectively); (v) R₅ is a) -D-E-F, wherein D is C₁₋₄alkylene (e.g., methylene, ethylene or prop-2-yn-1-ylene); E is arylene (e.g., phenylene); and F is aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, diazolyl, triazolyl, for example, pyrid-2-yl, imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example, pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl), piperidinyl (e.g., piperidin-2-yl), tetrahydro-2H-pyran-4-yl or morpholinyl), wherein F is optionally substituted with one or more halo or C₁₋₆alkyl (e.g., F is 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl, 4-fluorophenyl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl); or b) attached to one of the nitrogen atoms on the pyrazolo portion of Formula II and is a moiety of Formula A

wherein X, Y and Z are, independently, N or C, and R₈, R₉, R₁₁ and R₁₂ are independently H, halogen (e.g., Cl or F), and R₁₀ is C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl or oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more halo (e.g., F or Cl), C₁₋₄alkyl, for example R₁₀ is 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl, 4-fluorophenyl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl; (vi) R₆ is C₁₋₄alkyl (e.g., isopropyl or isobutyl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), arylC₁₋₄alkyl (e.g., benzyl), wherein the aryl or heteroaryl is optionally substituted with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy, C₃₋₈cycloalkyl, for example, R₆ is isopropyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 3-chlorophenyl or 4-fluorophenyl; (vii) n=0 or 1; (viii) when n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃ and R₁₄, are, independently, H or C₁₋₄alkyl, aryl, heteroaryl, (optionally hetero)arylC₁₋₄alkoxy, (optionally hetero)arylC₁₋₄alkyl or R₁₃ or R₁₄ can form a di-, tri- or tetramethylene bridge with R₂ or R₄; (ix) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl, in free or salt form; B) a compound of Formula III:

wherein (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂; (ii) L is a —O—; (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₄ is H or C₁₋₄alkyl (e.g., methyl, isopropyl) and R₂ and R₃ are, independently: H, C₁₋₆alkyl (e.g., methyl or isopropyl) optionally substituted with halo or hydroxy (e.g., R₂ and R₃ are both methyl, or R₂ is H and R₃ is methyl, ethyl, isopropyl or hydroxyethyl), aryl, heteroaryl, (optionally hetero)arylC₁₋₆alkoxy, (optionally hetero)arylC₁₋₆alkyl, or  R₂ and R₃ together with the carbon to which they are attached form a 3- to 6-membered ring; or  R₂ is H and R₃ and R₄ together form a di-, tri- or tetramethylene bridge  (pref. wherein the R₃ and R₄ together have the cis configuration, e.g., where the carbons carrying R₃ and R₄ have the R and S configurations, respectively); (v) R₅ is a) -D-E-F, wherein D is C₁₋₄alkylene (e.g., methylene, ethylene or prop-2-yn-1-ylene); E is arylene (e.g., phenylene); and F is aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, diazolyl, triazolyl, for example, pyrid-2-yl, imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example, pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl), piperidinyl (e.g., piperidin-2-yl), tetrahydro-2H-pyran-4-yl or morpholinyl), wherein F is optionally substituted with one or more halo or C₁₋₆alkyl (e.g., F is 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl, 4-fluorophenyl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl); or b) attached to one of the nitrogen atoms on the pyrazolo portion of Formula III and is a moiety of Formula A

wherein X, Y and Z are, independently, N or C, and R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F), and R₁₀ is C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl, oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more halo (e.g., F or Cl) or C₁₋₄alkyl; (vi) R₆ is: C₁₋₄alkyl (e.g., isopropyl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), wherein the aryl or heteroaryl is optionally substituted with one or more halo (e.g., F or Cl), hydroxy or C₁₋₆alkyl, for example, R₆ is 3-chlorophenyl or 4-fluorophenyl, (vii) n=0 or 1; (viii) when n=1, A is —C(R₁₃R₁₄)—, wherein R₁₃ and R₁₄, are, independently, H or C₁₋₄alkyl, aryl, heteroaryl, (optionally hetero)arylC₁₋₄alkoxy, (optionally hetero)arylC₁₋₄alkyl or R₁₃ or R₁₄ can form a di-, tri- or tetramethylene bridge with R₂ or R₄; (i) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl, in free or salt form; C) a compound of Formula IV:

wherein: (i) Q is —C(═S)—, —C(═N(R₂₀))—, —C(═O)— or CH₂; (ii) L is a —O—; (iii) R₁ is H or C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₅ is a) -D-E-F, wherein D is C₁₋₄alkylene (e.g., methylene, ethylene or prop-2-yn-1-ylene); E is arylene (e.g., phenylene); F is aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, diazolyl, triazolyl, for example, pyrid-2-yl, imidazol-1-yl, pyrazol-1-yl, 1,2,4-triazol-1-yl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), or heteroC₃₋₇cycloalkyl (e.g., pyrrolidinyl (for example, pyrrolidin-1-yl, pyrrolidin-2-yl or pyrrolidin-3-yl), piperidinyl (e.g., piperidin-2-yl), tetrahydro-2H-pyran-4-yl or morpholinyl), wherein F is optionally substituted with one or more halo or C₁₋₆alkyl (e.g., F is 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl, 4-fluorophenyl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl); or b) attached to one of the nitrogen atoms on the pyrazolo portion of Formula IV and is a moiety of Formula A

wherein X, Y and Z are, independently, N or C, and R₈, R₉, R₁₁ and R₁₂ are independently H or halogen (e.g., Cl or F), and R₁₀ is C₃₋₇cycloalkyl, hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl, oxadiazolyl (e.g., 1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more halo (e.g., F or Cl), C₁₋₄alkyl; (v) R₆ is: C₁₋₄alkyl (e.g., isopropyl), C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), wherein the aryl or heteroaryl is optionally substituted with one or more halo (e.g., F, Cl), hydroxy or C₁₋₆alkyl, for example, R₆ is 3-chlorophenyl or 4-fluorophenyl, (ii) R₂₀ is H, C₁₋₄alkyl (e.g., methyl) or C₃₋₇cycloalkyl, in free or salt form; D) a compound of Formula V:

wherein: (i) Q is —C(═O)—; (ii) L is —O—; (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo portion of Formula V and is a moiety of Formula A

wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are independently H, and R₁₀ is: hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl or oxodiazolyl (e.g., 1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more halo (e.g., F or Cl), C₁₋₄alkyl, for example Rois 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl, 4-fluorophenyl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl; (v) R₆ is C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), arylC₁₋₄alkyl (e.g., benzyl), wherein the aryl or heteroaryl is optionally substituted with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy, C₃₋₈cycloalkyl, for example, R₆ is isopropyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 3-chlorophenyl or 4-fluorophenyl, in free or salt form; E) a compound of Formula VI:

wherein: (i) Q is —C(═O)—; (ii) L is —O—; (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo portion of Formula VI and is a moiety of Formula A

wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are independently H, and R₁₀ is selected from piperidinyl (e.g., piperidin-2-yl), pyrrolidinyl (e.g., pyrrolidin-2-yl), pyridyl (for example pyrid-2-yl, pyrid-3-yl), diazolyl (e.g., pyrazol-1-yl), 6-fluoropyrid-2-yl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl; (v) R₆ is C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), arylC₁₋₄alkyl (e.g., benzyl), wherein the aryl or heteroaryl is optionally substituted with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy, C₃₋₈cycloalkyl, for example, R₆ is cyclopentyl, cyclohexyl, phenyl, 3-chlorophenyl or 4-fluorophenyl, in free or salt form; F) a compound of Formula VII:

wherein: (i) Q is —C(═O)—; (ii) L is —O—; (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo portion of Formula VI and is a moiety of Formula A

wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are independently H, and R₁₀ is selected from piperidinyl (e.g., piperidin-2-yl), pyrrolidinyl (e.g., pyrrolidin-2-yl), pyridyl (for example pyrid-2-yl, pyrid-3-yl), diazolyl (e.g., pyrazol-1-yl), 6-fluoropyrid-2-yl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl; (v) R₆ is selected from cyclopentyl, cyclohexyl, phenyl, 3-chlorophenyl or 4-fluorophenyl, in free or salt form; G) a compound of Formula VIII:

wherein: (i) Q is —C(═O)—; (ii) L is —O—; (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo portion of Formula VIII and is a moiety of Formula A

wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are independently H, and R₁₀ is pyrid-2-yl, 6-fluoropyrid-2-yl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl; (v) R₆ is phenyl or 4-fluorophenyl, in free or salt form.
 5. The Compound according to claim 3, wherein R₁₀ is selected from any of 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, in free or salt form.
 6. The Compound according to claim 1, wherein said compound is selected from any of the following:

in free or salt form.
 7. A pharmaceutical composition comprising a compound according to claim 3, in free or pharmaceutically acceptable salt form, in admixture with a pharmaceutically acceptable diluent or carrier.
 8. A method of treating any of the following conditions: Parkinson's disease, restless leg tremors, dyskinesias, Huntington's disease, Alzheimer's disease, drug-induced movement disorders, depression, attention deficit disorder, attention deficit hyperactivity disorder, bipolar illness, anxiety, sleep disorder, narcolepsy, cognitive impairment, dementia, Tourette's syndrome, autism, fragile X syndrome, psychostimulant withdrawal, drug addiction, cerebrovascular disease, stroke, congestive heart disease, hypertension or pulmonary hypertension, sexual dysfunction, asthma, chronic obstructive pulmonary disease, allergic rhinitis, as well as autoimmune and inflammatory diseases; female sexual dysfunction, exercise amenorrhoea, anovulation, menopause, menopausal symptoms, hypothyroidism, pre-menstrual syndrome, premature labor, infertility, irregular menstrual cycles, abnormal uterine bleeding, osteoporosis, multiple sclerosis, prostate enlargement, prostate cancer, estrogen-induced endometrial hyperplasia or carcinoma, any disease or condition characterized by low levels of cAMP and/or cGMP (or inhibition of cAMP and/or cGMP signaling pathways) in cells expressing PDE1, and/or by reduced dopamine D1 receptor signaling activity, any disease or condition that may be ameliorated by the enhancement of progesterone signaling, psychosis, schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, mania, such as in acute manic episodes bipolar disorder, traumatic brain injury; comprising administering an effective amount of a compound according to claim 3, in free or pharmaceutically acceptable salt form, to a patient in need of such treatment.
 9. The method of claim 8, wherein the condition is Parkinson's disease.
 10. The method of claim 8, wherein the condition is cognitive impairment.
 11. The method of claim 8, wherein the condition is narcolepsy.
 12. The method of claim 11 further comprising administering a compound or compounds selected from central nervous system stimulants, modafinil, antidepressants, and gamma hydroxybutyrate, to a patient in need thereof.
 13. The method of claim 8, wherein said condition is female sexual dysfunction.
 14. The method of claim 13, further comprising administering a compound or compounds selected from a group consisting of estradiol, estriol, estradiol esters, progesterone and progestins to a patient in need thereof.
 15. A method for the treatment of glaucoma or elevated intraocular pressure comprising topical administration of a therapeutically effective amount of a compound according to claim 3, in free or pharmaceutically acceptable salt form, in an ophthalmically compatible carrier to the eye of a patient in need thereof.
 16. The method according to claim 8, wherein the condition is traumatic brain injury.
 17. A method for lengthening or enhancing growth of the eyelashes by administering an effective amount of a prostaglandin analogue, e.g., bimatoprost, concomitantly, simultaneously or sequentially with an effective amount of a compound according to claim 3, in free or pharmaceutically acceptable salt form.
 18. (canceled)
 19. (canceled)
 20. (canceled)
 21. The compound according to claim 3, wherein said compound is a compound of Formula V:

wherein: (i) Q is —C(═O)—; (ii) L is —O—; (iii) R₁ is C₁₋₄alkyl (e.g., methyl or ethyl); (iv) R₅ is attached to one of the nitrogen atoms on the pyrazolo portion of Formula V and is a moiety of Formula A

wherein X, Y and Z are C, and R₈, R₉, R₁₁ and R₁₂ are independently H, and R₁₀ is: hetC₃₋₇cycloalkyl (e.g., pyrrolidinyl or piperidinyl, for example piperidin-2-yl or pyrrolidin-2-yl), aryl (e.g., phenyl), or heteroaryl (e.g., pyridyl (for example pyrid-2-yl, pyrid-3-yl, pyrid-4-yl), or thiadiazolyl (e.g., 1,2,3-thiadiazol-4-yl)), diazolyl (e.g., imidazol-1-yl or pyrazol-1-yl), triazolyl (e.g., 1,2,4-triazol-1-yl), tetrazolyl or oxodiazolyl (e.g., 1,2,4-oxodiazol-3-yl), wherein the aryl, heteroaryl, cycloalkyl and heterocycloalkyl are independently and optionally substituted with one or more halo (e.g., F or Cl), C₁₋₄alkyl, for example Rois 4-methyl-imidazol-1-yl, 1-methyl-imidazol-2-yl, 5-fluoropyrid-2-yl, 6-fluoropyrid-2-yl, 3-fluoropyrid-2-yl, 4-fluoropyrid-2-yl, 4,6-dichloropyrid-2-yl, 4-fluorophenyl, 1-methylpyrrolidin-3-yl, 1-methylpyrrolidin-2-yl, 1-ethylpiperidin-1-yl or 1-methylpiperidin-2-yl; (v) R₆ is C₃₋₇cycloalkyl (e.g., cyclopentyl or cyclohexyl), aryl (e.g., phenyl), heteroaryl (e.g., pyridyl, for example, pyrid-4-yl), arylC₁₋₄alkyl (e.g., benzyl), wherein the aryl or heteroaryl is optionally substituted with one or more halo (e.g., F, Cl), hydroxy, C₁₋₆alkyl, C₁₋₆alkoxy, C₃₋₈cycloalkyl, for example, R₆ is isopropyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 3-chlorophenyl or 4-fluorophenyl, and the remaining substituents are defined in claim 3, in free or salt form.
 22. The Compound according to claim 3, wherein R₅ is -D-E-F and D is C₁₋₄alkylene, E is arylene, and F is heteroaryl optionally substituted with one or more group selected from halo, C₁₋₄alkyl, haloC₁₋₄alkyl, and C₁₋₄alkoxy, in free or salt form.
 23. The compound according to claim 3, wherein said compound is selected from:

in free or salt form. 